Endovascular treatment of hepatic venous outflow obstruction after living-donor liver transplantation

Inferior Vena Cava Stenosis Following Orthotopic Liver Transplantation: Differentiating Points from False Positives

Orthotopic liver transplantation has become the treatment of choice for patients with end-stage liver disease. Various early or delayed vascular complications, including arterial pseudoaneurysm, thrombosis, or stenosis, and venous stenosis or occlusion, may lead to graft failure. Early detection and prompt management of such complications are essential to achieve successful transplantation and prevent the need for retransplantation. This report presents differentiating points, using computed tomography and digital subtraction angiography findings and measurement of pressure gradient across the stenotic lesion, that require immediate intervention in patients with inferior vena cava stenosis after orthotopic liver transplantation.

Understanding Local Hemodynamic Changes After Liver Transplant: Different Entities or Simply Different Sides to the Same Coin?

Liver transplantation is an extremely complex procedure performed in an extremely complex patient. With a successful technique and acceptable long-term survival, a new challenge arose: overcoming donor shortage. Thus, living donor liver transplant and other techniques were developed. Aiming for donor safety, many liver transplant units attempted to push the viable limits in terms of size, retrieving smaller and smaller grafts for adult recipients. With these smaller grafts came numerous problems, concepts, and definitions. The spotlight is now aimed at the mirage of hemodynamic changes derived from the recipients prior alterations. This article focuses on the numerous hemodynamic syndromes, their definitions, causes, and management and interconnection with each other. The aim is to aid the physician in their recognition and treatment to improve liver transplantation success.

Back table Preparation of the Right Lobe Live Donor Liver Allograft: A Crucial Part of the Adult Live Donor Liver Transplant Procedure

INTRODUCTION

We aimed to describe our procedure for vascular reconstruction and back table bench preparation for the right lobe live donor allograft. Live donor liver transplantation (LDLT) remains an important option for the expansion of the donor pool. The procedure has been widely used, and its success is dependent on a technically perfect operation with appropriate inflow and outflow of the allograft. Adequate preparation of the right lobe (RL) allograft prior to implantation remains a vital part of the procedure.

METHODS

Our technique of back table vascular reconstruction of the RL allograft has been performed using a hepatic vein patch venoplasty, inferior hepatic vein inclusion, portal vein reconstruction, and segment V and VIII reconstruction for all of our LDLTs.

RESULTS

Between March 2009 and January 2020, 321 consecutive adult LDLTs were performed and underwent back table reconstruction with the techniques described. During that time period, no patients had hepatic insufficiency. There was a single thrombosis of a superior mesenteric vein (SMV) to PV jump conduit.

CONCLUSIONS

Our technique of back table reconstruction of the LDLT right lobe graft remains a crucial part of the operative procedure. Our experience with RL grafts without middle hepatic vein (MHV) and our systematic approach for inflow and outflow reconstruction has yielded excellent results with no technical outflow issues and minimal inflow complications.

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.

Patency of Hemashield grafts versus ringed Gore-Tex grafts in middle hepatic vein reconstruction for living donor liver transplantation

Backgrounds/Aims

Owing to the short supply of homologous vein allografts, we previously used ringed Gore-Tex vascular grafts for middle hepatic vein (MHV) reconstruction in living donor liver transplantation. When ringed Gore-Tex grafts became unavailable, we used Hemashield vascular grafts. This study aimed to compare the patency and complication rates of Hemashield and ringed Gore-Tex grafts.

Methods

This retrospective two-arm study compared the study group that received Hemashield grafts (n=157) and the propensity score-matched control group that received ringed Gore-Tex grafts (n=157).

Results

In the Hemashield and Gore-Tex groups, the recipient age was 54.7±9.4 and 53.3±6.3 years; Model for End-stage Liver Disease scores were 15.9±9.2 and 16.9±8.3; and graft-recipient weight ratios were 1.07±0.24 and 1.10±0.23, respectively. In the Hemashield group, V5 reconstruction was performed using single (n=113, 72.0%), double (n=39, 24.8%), and triple (n=3, 1.9%) anastomoses. The proportion of double and triple anastomoses for V5 and V8 was higher in the Hemashield group than in the Gore-Tex group. Two (1.3%) patients required MHV conduit stenting owing to early thrombosis of the Hemashield graft. There was no difference in conduit occlusion- free patient survival rates between groups (p=0.91). The incidence of accidental conduit migration in the Hemashield and Gore-Tex groups was 0 (0%) and 2 (1.3%), respectively.

Conclusions

Hemashield grafts used in MHV reconstruction demonstrated acceptably high short- and mid-term patency rates, no incidences of conduit migration, easy handling, and good flexibility for length adjustment. Therefore, we suggest that the Hemashield graft is the preferentially suitable prosthetic material for MHV reconstruction.

Refined surgical techniques to improve the patency of cryopreserved iliac artery homografts for middle hepatic vein reconstruction during living donor liver transplantation

Purpose

A cryopreserved iliac artery homograft (IAH) has not been considered suitable for middle hepatic vein (MHV) reconstruction during living donor liver transplantation (LDLT), primarily due to the low patency from its small diameter. We revised our surgical techniques for MHV reconstruction using an IAH to improve its patency.

Methods

This study analyzed the causes of early conduit occlusion and developed revised techniques to address this that had clinical application.

Results

The potential risk factors for early conduit occlusion were the small IAH size, small graft in the segment V vein (V5) and segment VIII vein (V8) opening, and small recipient MHV-left hepatic vein stump. These factors were reflected to our revised surgical methods which included endarterectomy of the atherosclerotic plaque, unification of the internal and external iliac artery branches for large V5, and branch-patch arterioplasty for large V8. IAH endarterectomy, branch unification technique, and branch-patch arterioplasty were applied to 8, 5, and 5 patients, respectively and resulted in 1-month occlusion rates of 37.5%, 20.0%, and 40.0%, respectively. The overall patency rates of the IAH-MHV conduits in our 18 patients were 66.7% at 1 month, 38.9% at 3 months, and 33.3% at 1 year.

Conclusion

Our refined MHV reconstruction using an IAH improved short-term MHV conduit patency, but did not effectively prevent early conduit occlusion, particularly with a small- or medium-sized IAH. Individualized reconstruction designs during LDLT operation are needed when an IAH is used for a modified right liver graft.

Hemashield Vascular Graft Is a Preferable Prosthetic Graft for Middle Hepatic Vein Reconstruction in Living Donor Liver Transplantation

Background

Because of the supply shortage for homologous vein allografts, we previously used ringed Gore-Tex vascular grafts for middle hepatic vein (MHV) reconstruction in living donor liver transplantation. However, owing to the subsequent unavailability of ringed Gore-Tex grafts, we replaced them with Hemashield vascular grafts. This study aimed to compare the patency of Hemashield grafts with that of ringed Gore-Tex grafts.

Material/Methods

This was a retrospective double-arm study between the study group that used Hemashield grafts (n=63) and the historical control group that used ringed Gore-Tex grafts (n=126).

Results

In the Gore-Tex and Hemashield groups, mean age was 53.1±6.2 and 54.3±10.4 years; model for end-stage liver disease score was 16.5±8.3 and 17.5±9.9; and graft-recipient weight ratio was 1.11±0.23 and 1.12±0.25, respectively. In the Gore-Tex graft group, V5 reconstruction was done in single (n=107, 84.9%), double (n=17, 13.5%), and none (n=2, 1.6%). V8 reconstruction was done in single (n=95, 75.4%), double (n=1, 0.8%), and none (n=30, 23.8%). In the Hemashield group, V5 reconstruction was done in single (n=43, 68.3%), double (n=19, 30.2%), and triple (n=1, 1.6%). V8 reconstruction was done in single (n=45, 71.4%), double (n=9, 14.3%), and none (n=9, 14.3%). One-year conduit patency rates in the Gore-Tex and Hemashield groups were 54.8% and 71.6%, respectively (p=0.048).

Conclusions

MHV reconstruction using Hemashield vascular grafts demonstrated higher short-term patency rates than those associated with ringed Gore-Tex vascular grafts. We suggest that the Hemashield vascular graft is one of the best prosthetic materials for MHV reconstruction.

Endovascular stent placement for venous complications following pediatric liver transplantation: outcomes and indications

PURPOSE

Advances in interventional radiology (IVR) treatment have notably improved the prognosis of hepatic vein (HV) and portal vein (PV) complications following pediatric living donor liver transplantation (LDLT); however, graft failure may develop in refractory cases. Although endovascular stent placement is considered for recurrent stenosis, its indications are controversial.

METHODS

We enrolled 282 patients who underwent pediatric LDLT in our department from May 2001 to September 2016.

RESULTS

22 (7.8%) HV complications occurred after LDLT. Recurrence was observed in 45.5% of the patients after the initial treatment, and 2 patients (9.1%) underwent endovascular stent placement. The stents were inserted at 8 months and 3.8 years following LDLT, respectively. After stent placement, both patients developed thrombotic obstruction and are currently being considered for re-transplantation. 40 (14.2%) PV complications occurred after LDLT. Recurrence occurred in 27.5% of the patients after the initial treatment, and 4 patients (10.0%) underwent endovascular stent treatment. The stents of all the patients remained patent, with an average patency duration of 41 months.

CONCLUSION

Endovascular stent placement is an effective treatment for intractable PV complications following pediatric LDLT. However, endovascular stent placement for HV complications should be carefully performed because of the risk of intrastent thrombotic occlusion and the possibility of immunological venous injury.

Efficacy of repeated balloon venoplasty for treatment of hepatic venous outflow obstruction after pediatric living-donor liver transplantation: A single-institution experience

HVOO is a rare complication after LT and an important cause of graft failure. Balloon venoplasty is the first-line treatment for HVOO, but the effect of repeated balloon venoplasty and stent placement for HVOO recurrence after pediatric LDLT remains unclear. Between 1998 and 2016, 147 pediatric patients underwent LDLT in our institution. Among them, the incidence of HVOO and the therapeutic strategy were retrospectively reviewed. Ten patients were diagnosed with HVOO. All the patients underwent LLS grafts. Median age at the initial endovascular intervention was 2.7 years (range, 5 months-8 years). The median interval between the LDLT and the initial interventional radiology was 2.7 months (range, 29 days-35.7 months). Four patients experienced no recurrence after a single balloon venoplasty; 6 underwent balloon venoplasty more than 3 times because of HVOO recurrence; and 2 underwent stent placement due to the failure of repeated balloon venoplasty. All patients are alive with no symptoms of HVOO. The HVOO recurrence-free period after the last intervention ranged from 20 days to 15.5 years (median, 8.9 years). Repeated balloon venoplasty may prevent unnecessary stent placement to treat recurrent HVOO after pediatric LDLT.

Diagnosis, treatment and outcome of hepatic venous outflow obstruction in paediatric liver transplantation: 24-year experience at a single centre

BACKGROUND

Hepatic venous outflow obstruction after paediatric liver transplantation is an unusual but critical complication.

OBJECTIVES

To review the incidence, diagnosis and therapeutic modalities of hepatic venous outflow obstruction from a large national liver transplant unit.

MATERIALS AND METHODS

During the period from October 1992 to March 2016, 917 liver transplant procedures were performed with all types of grafts in 792 children. Transplants suspected to have early or delayed venous outflow obstruction were confirmed by percutaneous venography or surgical revision findings. Therapeutic intervention, recurrence and outcome were evaluated.

RESULTS

Twenty-six of 792 children (3.3%) experienced post-transplant hepatic venous outflow obstruction. These patients had been diagnosed from 1 day to 8.75 years after transplantation. Six occurred during the early post-transplant period; in three of them, the graft was lost. Seventeen patients were initially treated by balloon angioplasty with success; 11 of these experienced recurrences. Four stents were implanted; one was complicated by definitive occlusion. Three of the five surgical revisions were successful. The initial stenosis involved the inferior vena cava in 10 grafts, in isolation or associated with hepatic vein involvement. Mean follow-up was 79 months after transplantation. Eight grafts were lost.

CONCLUSION

Acute postoperative hepatic venous outflow obstruction was associated with poor prognosis. Diagnostic venography should be performed if there is any suspicion of venous outflow obstruction, even if first-line examinations are normal. Stenosis frequently involved the inferior vena cava. Angioplasty was a safe and efficient treatment for venous outflow obstruction despite frequent recurrence.

Balloon dilatation for treatment of hepatic venous outflow obstruction following pediatric liver transplantation

AIM

To assess the efficacy and safety of balloon dilatation for the treatment of hepatic venous outflow obstruction (HVOO) following pediatric liver transplantation.

METHODS

A total of 246 pediatric patients underwent liver transplantation at our hospital between June 2013 and September 2016. Among these patients, five were ultimately diagnosed with HVOO. Seven procedures (two patients underwent two balloon dilatation procedures) were included in this analysis. The demographic data, types of donor and liver transplant, interventional examination and therapeutic outcomes of these five children were analyzed. The median interval time between pediatric liver transplantation and balloon dilatation procedures was 9.8 mo (range: 1-32).

RESULTS

Five children with HVOO were successfully treated by balloon angioplasty without stent placement, with seven procedures performed for six stenotic lesions. All children underwent successful percutaneous intervention. Among these five patients, four were treated by single balloon angioplasty, and these patients did not develop recurrent stenosis. In seven episodes of balloon angioplasty across the stenosis, the pressure gradient was 12.0 ± 8.8 mmHg before balloon dilatation and 1.1 ± 1.5 mmHg after the procedures, which revealed a statistically significant reduction (P < 0.05). The overall technical success rate among these seven procedures was 100% (7/7), and clinical success was achieved in all five patients (100%). The patients were followed for 4-33 mo (median: 15 mo). No significant procedural complications or procedure-related deaths occurred.

CONCLUSION

Balloon dilatation is an effective and safe therapeutic option for HVOO in children undergoing pediatric liver transplantation. Venous angioplasty is also recommended in cases with recurrent HVOO.

Analysis of the MELD Score Impact in the Outcome of Endovascular Portal Vein Reconstruction

INTRODUCTION

Endovascular therapy represents a less invasive alternative to open surgery for reconstruction of the portal vein (PV) and the spleno-mesenteric venous confluence to treat Portal hypertension. The objective of this study is to determine if the Model for End-Stage Liver Disease (MELD) score is a useful method to evaluate the risk of morbidity and mortality during endovascular approaches.

MATERIAL AND METHODS

Patients that underwent endovascular reconstruction of the PV or spleno-mesenteric confluence were identified retrospectively. Data were collected from November 2011 to August 2016. The MELD score was calculated using international normalized ratio, serum billirubin and creatinine. Patients were grouped into moderate (≤ 15) and high (> 15) MELD. Associations of the MELD score on the postprocedural morbidity, mortality and vessels patency were assessed by two-sided Fisher's exact test.

RESULTS

Seventeen patients were identified; MELD score distribution was: ≤ 15 in 10 patients (59%) and > 15 in 7 (41%). Even distribution of severe PV thrombosis was treated in both groups, performing predominately jugular access in the high MELD score group (OR 0.10; 95%; CI 0.014-0.89; p = 0.052) in contrast to a percutaneous transhepatic access in the moderate MELD score group. Analysis comparing moderate and high MELD scores was not able to demonstrate differences in mortality, morbidity or patency rates.

CONCLUSION

MELD score did not prove to be a useful method to evaluate risk of morbidity and mortality; however a high score should not contraindicate endovascular approaches. In our experience a high technical success, good patency rates and low complication rates were observed.

Interventional radiology in the management of the liver transplant patient

Liver transplantation (LT) is commonly used to treat patients with end-stage liver disease. The evolution of surgical techniques, endovascular methods, and medical care has led to a progressive decrease in posttransplant morbidity and mortality. Despite these improvements, a multidisciplinary approach to each patient remains essential as the early diagnosis and treatment of the complications of transplantation influence graft and patient survival. The critical role of interventional radiology in the collaborative approach to the care of the LT patient will be reviewed. Liver Transplantation 23 1328-1341 2017 AASLD.

Longterm outcomes of stent placement for hepatic venous outflow obstruction in adult liver transplantation recipients

The purpose of this study was to evaluate the longterm outcomes of stent placement for a hepatic venous outflow obstruction in adult liver transplantation recipients. From June 2002 to March 2014, 23 patients were confirmed to have a hepatic venous outflow obstruction after liver transplantation (18 of 789 living donors [2.3%] and 5 of 449 deceased donors [1.1%]) at our institute. Among these patients, stent placement was needed for 16 stenotic lesions in 15 patients (12 males, 3 females; mean age, 51.7 years). The parameters that were documented retrospectively were technical success, clinical success, complications, recurrence, and the patency of the stent. The technical success rate was 100% (16/16). Clinical success was achieved in 11 of the 15 patients (73.3%). A major complication occurred in only 1 patient-a hepatic vein laceration during the navigation of the occluded segment. The median follow-up period was 33.5 months (range, 0.5-129.3 months), and the overall 1-, 3-, and 5-year primary patency rates of the stent were all 93.8%. One case of occlusion of the stent without clinical signs and symptoms was observed 5 days after the initial procedure. In this patient, the stent was recanalized by balloon angioplasty and showed patent lumen for 48 months of the subsequent follow-up period. In conclusion, stent placement is a safe and effective treatment modality with favorable longterm outcomes to treat hepatic venous outflow obstruction in adult liver transplantation recipients. Liver Transplantation 22 1554-1561 2016 AASLD.

Left lobe graft poses a potential risk of hepatic venous outflow obstruction in adult living donor liver transplantation

Hepatic venous outflow obstruction (HVOO) is a critical complication after living donor liver transplantation (LDLT). This study aimed to evaluate the incidence of HVOO and the risk factors for HVOO in adults. From 2005 to 2015, 430 adult LDLT patients (right lobe [RL] graft, 270 patients; left lobe [LL] graft, 160 patients) were enrolled and divided into no HVOO (n = 413) and HVOO (n = 17) groups. Patient demographics and surgical data were compared, and risk factors for HVOO were analyzed. Furthermore, the longterm outcomes of percutaneous interventions as treatment for HVOO were assessed. HVOO occurred in 17 (4.0%) patients. The incidence of HVOO in patients receiving a LL graft was significantly higher than in those receiving a RL graft (8.1% versus 1.5%; P = 0.001). The body weight and caliber of hepatic vein anastomosis in the HVOO group were significantly lower compared with the no HVOO group (P = 0.02 and P = 0.008, respectively). Multivariate analysis revealed that only LL graft was an independent risk factor for HVOO (OR, 4.782; 95% CI, 1.387-16.488; P = 0.01). Among 17 patients with HVOO, 7 patients were treated with single balloon angioplasty, and 9 patients who developed recurrence were treated with repeated interventions. Overall, 6 patients underwent stent placement: 1 at the initial procedure, 3 at the second procedure for early recurrence, and 2 following repeated balloon angioplasty (≥3 interventions). These 6 patients experienced no recurrence. Overall graft survival was not significantly different between the HVOO and no HVOO groups (P = 0.99). In conclusion, the use of a LL graft was associated with HVOO, and percutaneous interventions were effective for treating adult HVOO after LDLT. Liver Transplantation 22 785-795 2016 AASLD.

Usability of Cryopreserved Aortic Allografts for Middle Hepatic Vein Reconstruction During Living-Donor Liver Transplantation

Iliac vein allografts are suitable for middle hepatic vein (MHV) reconstruction during living-donor liver transplantation (LDLT), but their supply is often limited. Polytetrafluoroethylene (PTFE) grafts are easily available but have drawbacks of accidental gastric penetration and non-degradable foreign body. To replace the use of PTFE grafts, we started using cryopreserved aorta allografts (CAAs). This study presents the technical details and patency outcomes of using CAAs in MHV reconstruction. We reviewed the surgical techniques of CAA interposition and analyzed the patency rates in 74 patients who underwent LDLT during the 6-year study period. The two control groups received either cryopreserved iliac veins (n = 122) or PTFE grafts (n = 84). The surgical techniques for MHV reconstruction used to implant the CAA and PTFE grafts are very similar because the techniques developed for PTFE grafts were also applied to CAAs. We inserted an arterial patch at the liver cut surface because the CAA wall is too thick to perform direct anastomosis. Two patients (2.7 %) underwent MHV stenting during the first month. The 1-year patency rate was 69.7 % in the CAA group vs. 39.2 % in iliac vein group vs. 57.2 % in PTFE group (p = 0.000). The overall graft and patient survival rates did not differ depending on the MHV interposition vessel materials (p > 0.1). CAAs combined with small-artery patches demonstrated high patency rates that surpass other vessel grafts, and thus, we suggest that CAA can be reliably used for MHV reconstruction when CAA is available.

Surgical anterior cavoplasty for managing a case of early acute outflow obstruction after liver transplantation

HVOO following liver transplantation is rarely treated surgically because it tends to debut subacutely. However, acute HVOO is a surgical emergency that compromises the viability of the graft. We report a case of HVOO diagnosed intra-operatively during surgical revision for a suspected arterial thrombosis in a 10-month-old male recipient of a second graft (segments II-III) for familial intrahepatic cholestasis. HVOO was related to a stenosis at the first transplant hepato-caval anastomosis, left in place to obtain longer venous cuffs for retransplantation. An anterior cavoplasty was necessary to resolve the issue. The new anastomosis was created under total vascular exclusion after gaining control of the supradiaphragmatic vena cava, because the inferior vena cava was unsuitable for further surgery. This approach (normally used as a means to avoid sternotomy in patients with hepatic or renal tumours associated with venous thrombosis) allows adequate vascular control and, in selected cases, offers a surgical alternative for treating HVOO.

Long-term outcome of endovascular intervention in hepatic venous outflow obstruction following pediatric liver transplantation

The purpose of our study was to address the long-term outcome of angioplasty and stent placement for hepatic venous outflow obstruction following pediatric liver transplantation. From October 1999 to December 2011, 20 stenotic lesions were confirmed to constitute hepatic venous outflow obstruction in 18 pediatric patients (13 boys, 5 girls) among 152 pediatric patients following liver transplantation and were managed with endovascular intervention. Stent placement was favored over additional angioplasty in patients of preadolescent or adolescent age (>8 years old), after 1 or 2 sessions of balloon angioplasty. The primary patency and assisted primary patency were estimated using the Kaplan-Meier method. A total of 32 procedures (24 balloon angioplasties, 8 stent placements) were conducted. The technical success rate was 90.6% (29/32). Clinical success was achieved in 15 of 18 patients (clinical success rate of 83.3%). Major complications did not occur in our study. Median follow-up was 91.5 months (interquartile range, 54.7-137.3 months) for the 18 patients. The 1-year, 3-year, 5-year, and 10-year primary patencies of the 20 treated lesions were 63.5%, 57.8%, 57.8%, and 57.8%, respectively. The 1-year, 3-year, 5-year, and 10-year assisted-primary patencies of the lesions were 100%, 100%, 100%, and 100%, respectively. Of the 6 patients of preadolescent or adolescent age, 5 patients underwent stent placement procedures, and the stents were patent during the follow-up period of 57.3-162.5 months (median, 72.7 months). In conclusion, endovascular intervention is very effective in hepatic venous outflow obstruction following pediatric liver transplantation. In addition, early stent placement in patients of preadolescent or adolescent age can provide a safe and favorable long-term outcome.

Budd-Chiari syndrome after liver transplantation resulting from inferior vena cava occlusion at the suture line

A 64-year-old male with Budd-Chiari syndrome (BCS) due to inferior vena cava (IVC) occlusion after liver transplant presented with massive ascites and lower extremity edema. He was found to have chronic total occlusion of the supra-hepatic IVC with thrombosis in the infra-hepatic IVC, hepatic, renal, and iliac veins. Attempts to recanalize the occlusion by multiple operators failed. He was not a surgical candidate. The patient underwent venography of the IVC, and placement of a McNamara catheter for catheter-directed thrombolysis on the first day. The second day, he underwent right internal jugular access with contrast injections to mark the superior aspect of the occlusion via a Multipurpose catheter. An adult transseptal needle (Bard Electrophysiology Division C. R. Bard, Inc., Lowell, MA, USA) was used to create a tract through a 6 French Raabe Sheath and traverse the occlusion. A 10-mm Snare (Cook, Bloomington, IN, USA) cranially retracted the guidewire. Intravascular ultrasound was performed to further delineate the diameter of the IVC at the lesion before dilation with a 6.0 mm × 40 mm PTA balloon and a 10 mm × 29 mm Palmaz Stent (Cordis Corporation, Bridgewater, NJ, USA) deployment. The patient lost 24.6 kg in 2 weeks with resolution of ascites and pedal edema. <Learning objective: This case provides a unique approach to percutaneous intervention of inferior vena cava chronic total occlusion in the setting of Budd-Chiari syndrome post-liver transplant. There was use of an inferior and superior marker followed by use of transseptal needle to transverse the occlusion followed by balloon dilation and stent placement. While the disease and intervention have been described, the use of dual cranial/caudal markers and use of transseptal needle is unique to this particular case.>.

Hepatic venous outflow obstruction in pediatric liver transplantation: technical considerations in prevention, diagnosis, and management

HVOO creates significant diagnostic and management dilemmas in pediatric liver transplant recipients, particularly with TVGs (split or reduced-size grafts). Numerous technical variations for the hepatic vein to IVC anastomosis have been described to minimize the incidence of this complication, but no consensus for an optimal anastomotic technique exists. One hundred and thirty-four liver transplants (70 TVGs) were performed in 124 patients between 1994 and 2011. These were divided into two cohorts. Group 1 (95 transplants, 41 TVGs) utilized a continuous running anastomosis. Group 2 (39 transplants, 29 TVGs) implemented a triangulated (three-stitch) anastomosis. All were reviewed for demographics, diagnostics, interventions, and outcome. The overall HVOO incidence was seven of 134 transplants (5.2%) and six of 70 transplants utilizing TVGs (8.6%). Group 1 incidence was five of 41 (12.2%) compared with one of 29 (3.4%; p = 0.20, OR 3.89) in Group 2. Liver Doppler was employed in all patients, and only three suggested HVOO. All patients with HVOO underwent venogram, at a median of 81 days post-transplant. All underwent percutaneous venoplasty and required 1-6 treatments, all resulting in HVOO resolution. Incidence of HVOO has improved since adopting the triangulated anastomosis, although not to a level of statistical significance. US is not adequately sensitive to exclude HVOO. Venogram is recommended in patients with prolonged ascites, and venoplasty has been highly successful in HVOO treatment.

Interventional radiology in living donor liver transplant

The shortage of deceased donor liver grafts led to the use of living donor liver transplant (LDLT). Patients who undergo LDLT have a higher risk of complications than those who undergo deceased donor liver transplantation (LT). Interventional radiology has acquired a key role in every LT program by treating the majority of vascular and non-vascular post-transplant complications, improving graft and patient survival and avoiding, in the majority of cases, surgical revision and/or re-transplant. The aim of this paper is to review indications, diagnostic modalities, technical considerations, achievements and potential complications of interventional radiology procedures after LDLT.

Hepatic venous outflow obstruction after transplantation: outcomes for treatment with self-expanding stents

OBJECTIVES

To evaluate the safety and patency of self-expanding stents to treat hepatic venous outflow obstruction after orthotopic liver transplantation. To evaluate differences in the response between patients with early obstruction and patients with late obstruction.

MATERIAL AND METHODS

This is a retrospective analysis of 16 patients with hepatic venous outflow obstruction after liver transplantation treated with stents (1996-2011). Follow-up included venography/manometry, ultrasonography, CT, and laboratory tests. We did a descriptive statistical analysis of the survival of patients and stents, technical and clinical success of the procedure, recurrence of obstruction, and complications of the procedure. We also did an inferential statistical analysis of the differences between patients with early and late obstruction.

RESULTS

The mean follow-up period was 3.34 years (21-5,331 days). The technical success rate was 93.7%, and the clinical success rate was 81.2%. The rate of complications was 25%. The survival rates were 87.5% for patients and 92.5% for stents. The rate of recurrence was 12.5%. The rate of primary patency was 0.96 (95% CI 0.91-1) at 3 months, 0.96 (95% CI 0.91-1) at 6 months, 0.87 (95% CI 0.73-1) at 12 months, and 0.87 (95% CI 0.73-1) at 60 months. There were no significant differences between patients with early and late obstruction, although there was a trend toward higher rates of primary patency in patients with early obstruction (P=.091).

CONCLUSIONS

Treating hepatic venous outflow obstruction after orthotopic transplantation with self-expanding stents is effective, durable, and effective. There are no significant differences between patients with early obstruction and those with late obstruction.

Imaging of vascular complications and their consequences following transplantation in the abdomen

Transplantation is the surgical treatment of choice for end-stage organ failure. Transplantation procedures performed in the abdomen include liver, renal, pancreas, islet, intestinal, and multivisceral transplantations. Imaging plays a pivotal role in the posttransplantation setting for monitoring the transplant allograft and screening for complications. Knowledge of the surgical techniques employed in abdominal transplantation is essential because it facilitates radiologic understanding and interpretation of the posttransplantation anatomy. This article includes a basic description of the standard surgical techniques performed in the abdomen, with emphasis on the relevant vascular anastomotic reconstructions used. Posttransplantation complications can be broadly classified as vascular or nonvascular in origin. Many of these complications can be accurately depicted and characterized at imaging and dealt with definitively by using interventional radiology techniques, which can be graft- and life-saving and can obviate further complex surgical intervention. The article discusses imaging appearances of vascular complications and their consequences after transplantation in the abdomen. These vascular complications include arterial thrombosis, arterial stenosis, venous thrombosis and stenosis, arteriovenous fistula formation, and pseudoaneurysm formation. The relevant predisposing factors, clinical features, imaging appearances, and potential treatment options for vascular complications of various types of transplantation are presented in a logical and integrated fashion. Knowledge and imaging recognition of the posttransplantation vascular complications discussed in this article will aid radiologists in accurate imaging characterization and thereby facilitate appropriate clinical management and therapy.

Successful percutaneous transluminal balloon dilatation for hepatic venous outflow obstruction after pediatric liver transplantation: A series of cases

AIM

Whether percutaneous transluminal balloon dilatation (PTBD) or stent placement should be used in children with hepatic venous outflow obstruction (HVOO) is still controversial. The aim of the present study was to retrospectively describe experience in diagnosis and treatment of HVOO and to evaluate the outcome of PTBD in HVOO patients after pediatric liver transplantation (P-LT).

METHODS

From January 2001 to January 2011, 54 children received P-LT at our center. The clinical features of children with HVOO analyzed included demography, type of donor and liver transplant, the new-onset symptoms, liver function test, interventional examination, and treatment and outcome.

RESULTS

Three children were treated successfully with PTBD without stenting. All patients received percutaneous interventional management successfully. In the total of eight episodes of PTBD across the stenosis, the mean pressure gradient ± standard deviation was 16.6 ± 7.90 mmHg before PTBD and 6.8 ± 2.27 mmHg after PTBD. The difference was significant (P < 0.05). All of the three HVOO patients were still surviving with primary graft functioning normally until the last follow up.

CONCLUSION

HVOO after P-LT should be taken seriously. PTBD is an effective and safe treatment for HVOO in younger patients subjected to P-LT and re-venoplasty is recommended even in patients with recurrent HVOO.

Long-term outcome of percutaneous interventions for hepatic venous outflow obstruction after pediatric living donor liver transplantation: experience from a single institute

PURPOSE

To evaluate retrospectively the long-term outcome of percutaneous interventions for hepatic venous outflow obstruction (HVOO) occurring after pediatric living donor liver transplantation (LDLT).

MATERIALS AND METHODS

Between October 1997 and December 2012, 48 patients (24 boys, 24 girls; median age, 6 y) who had undergone LDLT were confirmed to have HVOO using percutaneous hepatic venography and manometry. All patients underwent percutaneous interventions, including balloon angioplasty with or without stent placement. Technical success, clinical success, patency rates, stent placement, and major complications were evaluated.

RESULTS

Technical success was achieved in 92 of 93 sessions (99.0%) and in 47 of 48 patients (97.9%), and clinical success was achieved in 41 of 48 patients (85.4%). During the follow-up period (range, 1-182 mo; median, 51.5 mo), 28 patients were treated with a single session of balloon angioplasty, and 20 patients who developed recurrent stenosis were treated with repeated percutaneous interventions. The rates of primary and primary-assisted patency at 1, 3, 5, and 10 years after balloon angioplasty were 64%, 57%, 57%, and 52% (primary patency) and 98%, 95%, 95%, and 95% (primary-assisted patency). Of six patients with stent placement, four had no recurrent HVOO after the stent placement, but two developed recurrent stenosis. The stent migrated to the right atrium in one patient.

CONCLUSIONS

Percutaneous interventions were effective treatments for HVOO after LDLT.

Standardization of modified right lobe grafts to minimize vascular outflow complications for adult living donor liver transplantation

BACKGROUND

After >2000 adult living donor liver transplants (LDLTs), we observed minimization of the complication rate using case-by-case modification of venous outflow reconstruction in right liver graft (RLG), standardization seeking intend to provide a hemodynamic- based, regeneration-compliant hepatic outflow reconstruction.

METHODS

We retrospectively examined 100 consecutive adult LDLT using modified RLG before and after application of RLG standardization to compare the 6-month incidences of vascular outflow complications.

RESULT

The right hepatic vein stenting rate for first 6 months was 5% in the customized group and 1% in the standardized group (P=.212). The middle hepatic vein stenting rate for first 6 months was 9% in the customized group and 4% in the standardized group (P=.373). The inferior right hepatic vein stenting rate for first 6 months was 12.8% in the customized group and 7.1% in the standardized group (P=.472). The overall 6-month patient survival rate was 94% in the customized group and 95% in the standardized group (P=.867). The overall incidence of significant RLG venous outflow complications was 19% in the customized group and 8% in the standardized group (P=.023).

CONCLUSION

Standardization as a universal graft model seemed to be more effective and feasible than conventional graft customization requiring individualized case-by-case modification.

Usability of ringed polytetrafluoroethylene grafts for middle hepatic vein reconstruction during living donor liver transplantation

Large vein allografts are suitable for middle hepatic vein (MHV) reconstruction, but their supply is often limited. Although polytetrafluoroethylene (PTFE) grafts are unlimitedly available, their long-term patency is relatively poor. We intended to enhance the clinical usability of PTFE grafts for MHV reconstruction during living donor liver transplantation (LDLT). Two sequential studies were performed. First, PTFE grafts were implanted as inferior vena cava replacements into dogs. Second, in a 1-year prospective clinical trial of 262 adults undergoing LDLT with a modified right lobe, MHV reconstruction with PTFE grafts was compared with other types of reconstruction, and the outcomes were evaluated. In the animal study, PTFE grafts induced strong inflammatory reactions and luminal thrombus formation, but the endothelial lining was well developed. In the clinical study, the reconstruction techniques were revised to make a composite PTFE graft with an artery patch on the basis of the results of the animal study. MHVs were reconstructed with cryopreserved iliac veins (n = 122), iliac arteries (n = 43), aortas (n = 13), and PTFE (n = 84), and these reconstructions yielded 6-month patency rates of 75.3%, 35.2%, 92.3%, and 76.6%, respectively. The overall 6-month patency rates for the iliac vein and PTFE grafts were similar (P = 0.92), but the 6-month patency rates with vein segment 5 were 51.0% and 34.7%, respectively (P = 0.001). The overall graft and patient survival rates did not differ among these 4 groups. In conclusion, ringed PTFE grafts combined with small vessel patches showed high patency rates comparable to those of iliac vein grafts; thus, they can be used for MHV reconstruction when other sizable vessel allografts are not available.

Hepatofugal portal venous flow on Doppler sonography after liver transplantation. Analysis of presumed causes based on radiologic and pathologic features

OBJECTIVES

The purpose of this study was to categorize hepatofugal portal venous flow on Doppler sonography after liver transplantation and to investigate its clinical importance and presumed causes based on radiologic and pathologic findings.

METHODS

This retrospective study was approved by our Institutional Review Board, and the requirement for informed consent was waived. Examination of our database over 4 years revealed 30 patients in whom Doppler sonography showed hepatofugal portal venous flow during follow-up periods. We investigated its occurrence and clinical features, including radiologic and pathologic findings, and classified the possible causes into 5 types: A, systemic problems; B, gross vascular abnormalities correctable by intervention; C, specific cardiac problems; D, microscopic abnormalities of the graft; and E, miscellaneous. We classified the patterns of hepatofugal portal venous flow into continuous hepatofugal or hepatofugal-dominant to-and-fro flow and hepatopetal-dominant to-and-fro flow, and we investigated the relationship of the presumed causes and flow patterns with the clinical course.

RESULTS

The incidence of hepatofugal portal venous flow was 2.38%. The overall mortality rate was 26.67% (95% confidence interval, 11.1%-42.9%): all patients (n = 5) in group A, 1 in group C, and 2 in group D, died. Possible cause type B and a mainly hepatopetal flow pattern were good prognostic factors (P = .031 and .018, respectively).

CONCLUSIONS

Hepatofugal portal venous flow reflects diverse pathologic conditions after liver transplantation, and its clinical importance also differs depending on the cause.

Reconstruction of inferior right hepatic veins in living donor liver transplantation using right liver grafts

Because revascularization of the inferior right hepatic vein (IRHV) is a major component of right liver graft (RLG) reconstruction, we assessed the surgical techniques and clinical outcomes of IRHV reconstruction so that we could formulate practical guidelines for standardized procedures. From July 2004 to February 2010, we performed separate IRHV reconstructions in 487 of 1142 adult RLG recipients (42.7%). These recipients included 364 patients with a natural single IRHV and 123 patients with multiple IRHVs; in the latter group, the IRHVs were unified by venoplasty, which enabled a single anastomosis. The 1-year stenosis rates for the single-vein and venoplasty groups were 23% and 18.9%, respectively, and the early stent insertion rates were 7.1% and 9.8%, respectively (P = 0.09). Late IRHV occlusion did not lead to graft dysfunction, and all large major IRHVs were patent. A morphometric analysis showed that IRHV stenosis was associated with IRHV stretching and an anastomotic level discrepancy. This led to refinements of the surgical techniques: IRHV orifices were shaped into funnels, and the IRHV anastomosis was accurately placed at the recipient inferior vena cava (IVC). In an ongoing prospective study of 35 patients, our funneling unification venoplasty resulted in only 1 episode (2.9%) of early IRHV stenosis requiring stenting at a median follow-up of 8 months. The final configurations of the reconstructed IRHVs after funneling unification venoplasty and extensive IVC dissection were very similar to those of the native donor liver. In conclusion, we suggest that in combination with extensive recipient IVC dissection, funneling and unification venoplasty techniques are useful for securely reconstructing single or multiple IRHVs during the implantation of RLGs.

Multimodality imaging of normal hepatic transplant vasculature and graft vascular complications

Orthotopic liver transplantation is an important treatment option for patients with end-stage liver disease. Advances in surgical technique, along with improvements in organ preservation and immunosuppression have improved patient outcomes. Post-operative complications, however, can limit this success. Ultrasound is the primary imaging modality for evaluation of hepatic transplants, providing real-time information about vascular flow in the graft. Graft vascular complications are not uncommon, and their prompt recognition is crucial to allow for timely graft salvage. A multimodality approach including CT angiography, MRI, or conventional angiography may be necessary in cases of complex transplant vascular anatomy or when sonography and Doppler are inconclusive to diagnose the etiologies of these complications. The purpose of this article is to familiarize radiologists with the normal post-transplant vascular anatomy and the imaging appearances of the major vascular complications that may occur within the hepatic artery, portal vein, and venous outflow tract, with an emphasis on ultrasound.

Interventional radiology in the treatment of the complications of organ transplant in the pediatric population-part 2: the liver

Organ transplantation continues to grow in demand in the pediatric population. The liver is the second most common organ that is transplanted in the pediatric population, but it results in the greatest number of interventional procedures. Transplant continues to be the preferred treatment for end-stage liver failure in children and has been shown to prolong life. There are several significant differences in liver transplantation between adults and children. They include different indications and diseases leading to transplant, the smaller body size of children, and differences in the surgical techniques used to implant the liver. These differences have led to a set of complications that is unique to or is more frequently seen in the transplanted child. The complications require interventional solutions tailored to the special needs of children. This paper will examine the complications that are encountered and the technical challenges that the interventionalist must address to successfully treat this subgroup of children. The purpose of this paper is to present the techniques and "pearls" that we have found to be helpful in treating this group of patients that in many ways is the most challenging in all of pediatric intervention.

Vascular complications following liver transplantation

Vascular complications (stenosis or thrombosis of the hepatic artery, portal vein or hepatic vein) are a relatively common occurrence following liver transplantation. Routine screening with ultrasound is critical to early detection of these complications. Careful application of standard interventional techniques (diagnostic catheter angiography, balloon angioplasty with selective stenting) may be used to confirm the ultrasound findings, treat the underlying lesions, and contribute to long-term graft survival.

Acute outflow obstruction of hepatic veins in rabbits: quantitative analysis of hepatic perfusion with contrast-enhanced sonography

OBJECTIVES

To compare time-enhancement curve parameters of contrast-enhanced sonography in acute partial hepatic venous outflow obstruction with those of a baseline study.

METHODS

Contrast-enhanced sonography was performed in 11 rabbits with bolus administration of a sulfur hexafluoride contrast agent (0.1 mL/kg). After baseline scanning for 3 minutes, a 5.3F balloon catheter was placed into the left hepatic vein. Obstruction was artificially induced by 0.4-mL balloon inflation, and sonography was repeatedly performed thereafter. On images stored with 1-second intervals, 2 × 2-mm regions of interest were placed, and mean luminosity was measured. Time-enhancement curves were plotted, and contrast arrival times, peak enhancement values, peak enhancement times, 50% wash-out times, and 3-minute wash-out rates were obtained. Paired t tests were performed to evaluate the significance of differences in the parameters between baseline and obstruction.

RESULTS

On baseline sonography, the median contrast arrival time, peak enhancement value, peak enhancement time, 50% wash-out time, and 3-minute wash-out rate were 6 (range, 4-8; mean ± SD, 5.9 ± 1.2) seconds, 188.5 (104.7-209.5; 178.4 ± 33.1) arbitrary units, 19 (14-27; 19.8 ± 4.1) seconds, 75 (60-101; 78.2 ± 13.9) seconds, and 89.7% (81.3%-95.1%; 88.4% ± 4.9%), respectively. With obstruction, those values were 7 (5-12; 6.9 ± 2.3) seconds, 202.8 (98.2-215.1; 186.0 ± 39.3) arbitrary units, 31 (17-59; 32 ± 11.6) seconds, 101 (47-136; 96.2 ± 23.6) seconds, and 79.2% (66.2%-88.8%; 79.1% ± 7.6%). Compared with baseline, the peak enhancement time was significantly delayed from 19 to 31 seconds (P = .0027), 50% wash-out time significantly delayed from 75 to 101 seconds (P = .0209), and 3-minute wash-out rate significantly decreased from 89.7% to 79.2% (P < .0001) with obstruction, but there were no significant differences in contrast arrival times and peak enhancement values (P = .0756 and .2179).

CONCLUSIONS

Contrast-enhanced sonography can provide quantitative assessment of microbubble congestion in partial hepatic venous outflow obstruction. The peak enhancement time and 50% wash-out time are delayed and 3-minute wash-out rate is decreased in rabbits with artificially induced obstruction compared with a baseline study.

Morphometric analysis of conformational changes in hepatic venous system after right lobe living donor liver transplantation

AIM

  After living donor liver transplantation (LDLT), the graft liver regenerates to the standard liver volume. However, little is known about the influence of this phenomenon on the hepatic venous system.

METHODS

  Fourteen right lobe LDLT without the middle hepatic vein were included in this study. Computed tomography before and 1 month after LDLT was performed to measure the inflow angle of the right hepatic vein (RHV), the aspect ratio of the inferior vena cava (IVC), the coordinate position of IVC and diameter of RHV. In addition, the regeneration index (RI) was determined on each liver segment.

RESULTS

  RHV showed a clockwise rotation at early postoperative months, the average increase of the inflow angle being 14.5 ± 15.6 (mean ± standard deviation) degrees. IVC was shifted from right to left with a deformity to a long oval shape on horizontal sections. The center of IVC moved dorsally at an average of 0.55 ± 0.77 cm and leftward at an average of 0.82 ± 0.89 cm. Diameter of RHV decreased at an average of 0.65 ± 0.39 cm at its root. The extent of liver regeneration was more prominent in the posterior segment as compared to the anterior segment, the average RI values being 1.65 ± 0.65 and 1.17 ± 0.44, respectively (P < 0.05). Hepatic vein outflow block (HVOB) was encountered in two patients with a marked conformational deformity observed in the hepatic venous system at early postoperative months after LDLT.

CONCLUSION

  After right lobe LDLT, the hepatic venous system exhibits a profound conformational change, which most likely plays a role in the onset of HVOB.

Hepatic venous outflow obstruction in pediatric living donor liver transplantation using left-sided lobe grafts: Kyoto University experience

The goals of this study were to evaluate the incidence of hepatic venous outflow obstruction (HVOO) in pediatric patients after living donor liver transplantation (LDLT) using left-sided lobe grafts and to assess the therapeutic modalities used for the treatment of this complication at a single center. Four hundred thirteen primary LDLT procedures were performed with left-sided lobe grafts between 1996 and 2006. All transplants identified with HVOO from a cohort of 380 grafts with survival greater than 90 days were evaluated with respect to the patient demographics, therapeutic intervention, recurrence, and outcome. Seventeen cases (4.5%) were identified with HVOO. Eight patients experienced recurrence after the initial balloon venoplasty. Two patients finally required stent placement after they experienced recurrence shortly after the initial balloon venoplasty. A univariate analysis revealed that a smaller recipient-to-donor body weight ratio and the use of reduced grafts were statistically significant risk factors. The cases with grafts with multiple hepatic veins had a higher incidence of HVOO. In conclusion, the necessity of repeated balloon venoplasty and stent placement was related to poor graft survival. Therefore, the prevention of HVOO should be a high priority in LDLT. When grafts with multiple hepatic veins and/or significant donor-recipient size mismatching are encountered, the use of a patch graft is recommended. Stent placement should be carefully considered because of the absence of data on the long-term patency of stents and stent-related complications. New stenting devices, such as drug-eluting and biodegradable stents, may be promising for the management of HVOO.

Transsplenic endovascular therapy of portal vein stenosis and subsequent complete portal vein thrombosis in a 2-year-old child

A complex catheter intervention for portal vein stenosis and subsequent complete thrombosis after split-liver transplantation was performed using transsplenic access to the portal vein circulation. The combination of intrahepatic, local thrombolysis and extrahepatic portal vein angioplasty performed twice on 2 consecutive days followed by anticoagulation with a high dose of heparin and clopidogrel completely resolved portal vein stenosis and thrombosis. Postinterventional angiographic and serial ultrasound examinations confirmed that the endovascular therapy was successful. In selected patients, percutaneous transsplenic access to the portal vein circulation may be used for diagnostic and therapeutic interventions even in early childhood.

Percutaneous transluminal venoplasty after venous pressure measurement in patients with hepatic venous outflow obstruction after living donor liver transplantation

PURPOSE

The aim of this study was to evaluate retrospectively the outcome of percutaneous transluminal venoplasty (PTV) after venous pressure measurement in patients with hepatic venous outflow obstruction following living donor liver transplantation (LDLT).

MATERIALS AND METHODS

We studied 24 consecutive patients suspected of having hepatic venous outflow obstruction after LDLT. Pressure gradients were measured proximal and distal to the lesion, and gradient values >3 mmHg were considered hemodynamically significant. We evaluated the technical success, complications, outcome of venoplasty and recurrence, and the patency rate.

RESULTS

In all, 11 female patients manifested a pressure gradient >3 mmHg across the anastomotic site; they underwent subsequent PVT. The initial balloon venoplasty procedure was technically successful in 10 of the 11 patients (91%), and the pressure gradient was reduced from 5.8 to 1.1 mmHg (P < 0.01). Clinical improvement was observed in 9 of these 10 patients; one patient failed to improve and underwent retransplantation. Recurrent obstruction occurred in four patients; they underwent PTV with (n = 2) or without (n = 2) stent placement. There were no major procedural complications.

CONCLUSION

PTV following venous pressure measurement is an effective and safe treatment for venous outflow obstruction in patients subjected to LDLT. In patients with recurrent obstruction, re-venoplasty is recommended.

Compressive stenosis of the left hepatic vein as a pathogenesis of postresectional liver failure: a case report

Introduction

Postresectional liver failure (PLF) is a devastating and fatal complication of major hepatic resection, and we do not have a full understanding of the pathogenic mechanisms involved. No reliable treatment other than liver transplantation currently exists for PLF.

Case presentation

A 46-year-old Japanese man experienced PLF after an extended right hepatectomy for liver malignancy. Seven months after surgery, the patient's Model for End-Stage Liver Disease (MELD) score had reached 23. Doppler ultrasound study and three-dimensional computed tomography images showed a stenosed left hepatic vein compressed by surrounding hypertrophied hepatic parenchyma. Transluminal balloon angioplasty and stent placement therapy were conducted eight months after surgery. The pressure gradient between the hepatic vein and right atrium decreased from 13 to 3 mmHg after stent placement. Thereafter, the patient recovered.

Conclusion

Hepatic venous compression by surrounding hypertrophied hepatic parenchyma might, at least in part, be associated with the occurrence of PLF. Surgeons should bear this possibility in mind when confronted with cases of PLF, as early diagnosis and stent placement improves patients' chances of recovery.

Long-term efficacy of stent placement for treating inferior vena cava stenosis following liver transplantation

The aims of this study were to evaluate both the efficacy of stent placement for treating inferior vena cava (IVC) stenosis and the patency of hepatic veins (HVs) following IVC stent placement. Fourteen hepatic transplant recipients underwent stent placement to treat IVC stenosis. The median interval between transplantation and stent placement was 32 days. Stents varied from 20-36 mm in diameter and were 60-120 mm long. We retrospectively analyzed the technical and clinical success, changes of hepatic venous flow, and the patency of the IVC stents. Stent placement was successful in all patients. Clinical success was achieved in 12 patients. Four patients underwent HV balloon angioplasty or stent placement through IVC stent meshes either immediately (n = 1) or 12-110 days after (n = 3) IVC stent placement. Nine of the 12 patients were healthy when this manuscript was completed, and the last follow-up computed tomography scan obtained at a median of 65.3 months after IVC stent placement revealed the patency of the stent-placed IVC and HVs. IVC stent placement seems to be an effective treatment with an excellent, long-term patency for treating posttransplant stenosis, although the possibility of hepatic venous outflow abnormalities following IVC stent placement should also be considered.

Management of venous stenosis in living donor liver transplant recipients

AIM: To retrospectively evaluate the management and outcome of venous obstruction after living donor liver transplantation (LDLT).

METHODS: From February 1999 to May 2009, 1 intraoperative hepatic vein (HV) tension induced HV obstruction and 5 postoperative HV anastomotic stenosis occurred in 6 adult male LDLT recipients. Postoperative portal vein (PV) anastomotic stenosis occurred in 1 pediatric left lobe LDLT. Patients ranged in age from 9 to 56 years (median, 44 years). An air balloon was used to correct the intraoperative HV tension. Emergent surgical reoperation, transjugular HV balloon dilatation with stent placement and transfemoral venous HV balloon dilatation was performed for HV stenosis on days 3, 15, 50, 55, and 270 after LDLT, respectively. Balloon dilatation followed with stent placement via superior mesenteric vein was performed for the pediatric PV stenosis 168 d after LDLT.

RESULTS: The intraoperative HV tension was corrected with an air balloon. The recipient who underwent emergent reoperation for hepatic stenosis died of hemorrhagic shock and renal failure 2 d later. HV balloon dilatation via the transjugular and transfemoral venous approach was technically successful in all patients. The patient with early-onset HV stenosis receiving transjugular balloon dilatation and stent placement on the 15th postoperative day left hospital 1 wk later and disappeared, while the patient receiving the same interventional procedures on the 50th postoperative day died of graft failure and renal failure 2 wk later. Two patients with late-onset HV stenosis receiving balloon dilatation have survived for 8 and 4 mo without recurrent stenosis and ascites, respectively. Balloon dilatation and stent placement via the superior mesenteric venous approach was technically successful in the pediatric left lobe LDLT, and this patient has survived for 9 mo without recurrent PV stenosis and ascites.

CONCLUSION: Intraoperative balloon placement, emergent reoperation, proper interventional balloon dilatation and stent placement can be effective as a way to manage hepatic and PV stenosis during and after LDLT.

Hepatic outflow obstruction at middle hepatic vein tributaries or inferior right hepatic veins after living donor liver transplantation with modified right lobe graft: comparison of CT and Doppler ultrasound

OBJECTIVE

The objective of our study was to compare CT and Doppler ultrasound in the diagnosis of hepatic outflow obstruction at the middle hepatic vein (MHV) tributaries and inferior right hepatic veins (RHVs) after living donor liver transplantation (LDLT) with modified right lobe grafts.

MATERIALS AND METHODS

Thirty-seven venographies were performed in 36 patients after LDLT with modified right lobe grafts, evaluating 51 MHV tributaries and 25 inferior RHVs. They were classified as obstructed or nonobstructed. On Doppler ultrasound or CT, flow patterns of the MHV tributaries and inferior RHVs or the relative parenchymal attenuation, enhancement, and opacification of these veins were evaluated for the diagnosis of hepatic outflow obstruction. McNemar tests were performed to compare the diagnostic values of Doppler ultrasound and CT.

RESULTS

On the basis of hepatic venography, 33 MHV tributaries were categorized as obstructed and 18 as nonobstructed, and 16 inferior RHVs were categorized as obstructed and nine as nonobstructed. For the diagnosis of MHV tributary obstruction, Doppler ultrasound was more sensitive and accurate, although less specific, than CT (97% vs 39%, respectively, p < 0.001; 86% vs 61%, p = 0.0209; 67% vs 100%, p = 0.0412). Similarly, Doppler ultrasound was more sensitive (94% vs 31%, respectively) and accurate (84% vs 56%) than CT, although less specific (67% vs 100%), for the diagnosis of inferior RHV obstruction, with a statistical significance only for sensitivity (p = 0.002, 0.092, and 0.248, respectively).

CONCLUSION

Doppler ultrasound is more sensitive and accurate than CT for the detection of obstruction at the MHV tributaries and inferior RHVs in patients after LDLT using modified right lobe grafts. Although current CT criteria produce high specificity and may reduce unnecessary invasive venographies, optimal CT criteria with acceptable sensitivity should be reestablished.