Portal vein stenosis in children with segmental liver transplants: treatment with percutaneous transhepatic venoplasty

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

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

Portal Vein Complications After Adult Living Donor Liver Transplantation: Time of Onset and Deformity Patterns Affect Long-Term Outcomes

Portal vein complications (PVCs) after adult living donor liver transplantation (LDLT) are potentially lethal. We categorized PVCs by the time of onset (early versus late, <1 month versus ≥1 month, respectively) and deformity patterns (portal vein stenosis [PVS], portal vein thrombosis [PVT], and portal vein occlusion [PVO]) to establish optimal treatment strategies. Overall, 35/322 (10.9%) recipients developed PVCs between 2000 and 2019. Pretransplant PVT (odds ratio [OR], 15.20; 95% confidence interval [CI], 3.70-62.40; P < 0.001) was the only independent risk factor for PVS. In contrast, male sex (OR, 5.57; 95% CI, 1.71-18.20; P = 0.004), pretransplant PVT (OR, 4.79; 95% CI, 1.64-14.00; P = 0.004), and splenectomy (OR, 3.24; 95% CI, 1.23-8.57; P = 0.018) were independent risk factors for PVT. PVS was successfully treated with interventional radiology regardless of its time of onset. On the other hand, late PVT and PVO had significantly lower treatment success rates (2/15, 13%) compared with those that occurred in the early period (10/11, 91%) despite aggressive intervention (P < 0.001). Deformity patterns had a significant impact on the 5-year cumulative incidence of graft loss as a result of PVC (PVO + Yerdel grades 2-4 PVT group [n = 16], 41% versus PVS + Yerdel grade 1 PVT group [n = 19], 0%; P = 0.02). In conclusion, late grades 2 to 4 PVT and PVO are refractory to treatment and associated with poor prognoses, whereas PVS has a good prognosis regardless of time of onset. A tailored approach according to the time of onset and deformity patterns of PVC is essential.

Portal vein obstruction after pediatric liver transplantation: A systematic review of current treatment strategies

INTRODUCTION

Portal vein obstruction (PVO) is a significant vascular complication after liver transplantation (LT) in pediatric patients. Current treatment strategies include percutaneous transluminal angioplasty (PTA), with or without stent placement, mesorex bypass (MRB), splenorenal shunt, mesocaval shunt, endovascular recanalization (EVR), splenic artery embolization and splenectomy. However, specific characteristics of patients undergoing intervention and selection of individual treatment and its efficacy have remained unclear. This review systematically analyzed biochemical and clinical characteristics, selection of treatment, efficacy, and post-procedural complications.

METHODS

We systematically searched PubMed and Embase between January 1995 and March 2021 for studies on the management of PVO after LT. We analyzed the reports for biochemical and clinical characteristics at the timing of the intervention in different patients, selection of treatment, and reported efficacies.

RESULTS

We found 22 cohort studies with 362 patients who had the following characteristics: biliary atresia (83%), living-donor LT (85%), thrombocytopenia (73%), splenomegaly (40%), ascites (16%), or gastrointestinal bleeding (26%). The 3-year primary patency of PTA without stent placement was similar to that with stent placement (70%-80% and 43%-94%, respectively). MRB was used as an initial treatment with a 3-year patency of 75% to 100%. One study showed that 5-year primary patency of EVR was 80%. Secondary patency was 90% to 100% after 3 years in all studies with PTA alone, PTA/stent placement, and stent placement alone.

CONCLUSION

This is the first review of all treatment protocols in PVO after pediatric LT. We showed that an important group of patients has severe symptoms of portal hypertension. Efficacy of all treatment modalities was high in the included studies which make them important modalities for these patients.

Liver Transplantation in Children: An Overview of Organ Allocation and Surgical Management

Liver transplantation is the standard treatment for children with end-stage liver disease, primary hepatic neoplasms, or liver-localized metabolic defects. Perioperative mortality is almost absent, and long-term survival exceeds 90%. Organ shortage is managed thanks to advances in organ retrieval techniques; living donation and partial liver transplantation almost eliminated waiting list mortality, thus leading to expanding indications for transplantation. The success of pediatric liver transplantation depends on the prompt and early referral of patients to transplant Centers and on the close and integrated multidisciplinary collaboration between pediatricians, hepatologists, surgeons, intensivists, oncologists, pathologists, coordinating nurses, psychologists, and social workers.

Portal vein stent placement after hepatobiliary and pancreatic surgery

Purpose

To evaluate the long-term outcomes of percutaneous transhepatic stent placement for portal vein (PV) stenosis after liver transplantation (LT) and hepato-pancreato-biliary (HPB) surgery.

Methods

Retrospective study of 455 patients who underwent LT and 522 patients who underwent resection of the pancreatic head between June 2011 and February 2016. Technical success, clinical success, patency, and complications were evaluated for both groups.

Results

A total of 23 patients were confirmed to have postoperative PV stenosis and were treated with percutaneous transhepatic PV stent placement. The technical success rate was 100%, the clinical success rate was 80%, and the long-term stent patency was 91.3% for the entire study population. Two procedure-related hemorrhages and two early stent thromboses occurred in the HPB group while no complications occurred in the LT group. A literature review of selected studies reporting PV stent placement for the treatment of PV stenosis after HPB surgery and LT showed a technical success rate of 78–100%, a clinical success rate of 72–100%, and a long-term patency of 57–100%, whereas the procedure-related complication rate varied from 0–33.3%.

Conclusions

Percutaneous transhepatic PV stent is a safe and effective treatment for postoperative PV stenosis/occlusion in patients undergoing LT regardless of symptoms. Due to increased risk of complications, the indication for percutaneous PV stent placement after HPB surgery should be limited to patients with clinical symptoms after an individual assessment.

Liver Transplantation

The field of liver transplantation has changed since the MELD scoring system became the most widely used donor allocation tool. Due to the MELD-based allocation system, sicker patients with higher MELD scores are being transplanted. Persistent organ donor shortages remain a challenging issue, and as a result, the wait-list mortality is a persistent problem for most of the regions. This chapter focuses on deceased donor and live donor liver transplantation in patients with complications of portal hypertension. Special attention will also be placed on donor-recipient matching, perioperative management of transplant patients, and the impact of hepatic hemodynamics on transplantation.

Jejunal varices diagnosed by capsule endoscopy in patients with post-liver transplant portal hypertension

Portal hypertension secondary to portal vein obstruction following liver transplant occurs in 5%-10% of children. Jejunal varices are uncommon in this group. We present a case series of children with significant GI blood loss, negative upper endoscopy, and jejunal varices detected by CE. Case series of patients who had CE for chronic GI blood loss following liver transplantation. Three patients who had their initial transplants at a median age of 7 months were identified at our institution presenting at a median age of 8 years (range 7-16 years) with a median Hgb of 2.8 g/dL (range 1.8-6.8 g/dL). Upper endoscopy was negative for significant esophageal varices, gastric varices, and bleeding portal gastropathy in all three children. All three patients had significant jejunal varices noted on CE in mid-jejunum. Jejunal varices were described as large prominent bluish vessels underneath visualized mucosa, one with evidence of recent bleeding. The results led to venoplasty of the portal vein in two patients and a decompressive shunt in one patient with resolution of GI bleed and anemia. CE is useful to diagnose intestinal varices in children with portal hypertension and GI bleeding following liver transplant.

Therapeutic efficacy and stent patency of transhepatic portal vein stenting after surgery

AIM

To evaluate portal vein (PV) stenosis and stent patency after hepatobiliary and pancreatic surgery, using abdominal computed tomography (CT).

METHODS

Percutaneous portal venous stenting was attempted in 22 patients with significant PV stenosis (> 50%) - after hepatobiliary or pancreatic surgery - diagnosed by abdominal CT. Stents were placed in various stenotic lesions after percutaneous transhepatic portography. Pressure gradient across the stenotic segment was measured in 14 patients. Stents were placed when the pressure gradient across the stenotic segment was > 5 mmHg or PV stenosis was > 50%, as observed on transhepatic portography. Patients underwent follow-up abdominal CT and technical and clinical success, complications, and stent patency were evaluated.

RESULTS

Stent placement was successful in 21 patients (technical success rate: 95.5%). Stents were positioned through the main PV and superior mesenteric vein (n = 13), main PV (n = 2), right and main PV (n = 1), left and main PV (n = 4), or main PV and splenic vein (n = 1). Patients showed no complications after stent placement. The time between procedure and final follow-up CT was 41-761 d (mean: 374.5 d). Twenty stents remained patent during the entire follow-up. Stent obstruction - caused by invasion of the PV stent by a recurrent tumor - was observed in 1 patient in a follow-up CT performed after 155 d after the procedure. The cumulative stent patency rate was 95.7%. Small in-stent low-density areas were found in 11 (55%) patients; however, during successive follow-up CT, the extent of these areas had decreased.

CONCLUSION

Percutaneous transhepatic stent placement can be safe and effective in cases of PV stenosis after hepatobiliary and pancreatic surgery. Stents show excellent patency in follow-up abdominal CT, despite development of small in-stent low-density areas.

Percutaneous transhepatic portal vein stenting for malignant portal vein stenosis secondary to recurrent perihilar biliary cancer

BACKGROUND

Transhepatic portal vein (PV) stenting has been shown to be one of the most important treatments for patients with PV stenosis caused by hepatopancreatobiliary malignancy.

METHODS

Ten consecutive patients with PV stenosis caused by the recurrence of a perihilar biliary malignancy underwent transhepatic PV stenting. A self-expandable metallic stent was deployed at the stenosis site. The patients were retrospectively analyzed with regard to the procedure, complications, and survival after the stent placement.

RESULTS

The median interval between the primary resection and the PV stenting was 22 months. The initial hepatic resection was a left trisectionectomy with caudate lobectomy in seven patients, a left hepatectomy with caudate lobectomy in one patient, a right anterior sectionectomy with caudate lobectomy following a left hepatectomy in one patient and a partial liver resection in one patient. The angle of the PV around the stenosis was greater in the patients with PV stenosis located in the right posterior PV. Eight patients with successful PV stent placement were able to receive anticancer treatment, with a median survival of 14 months. The remaining two patients without successful PV stent placement survived less than 6 months.

CONCLUSIONS

Portal vein stenting might offer relief from the symptoms associated with PV hypertension and the opportunity for sustainable anticancer therapy in patients with recurrent perihilar biliary malignancy.

Pediatric liver transplant portal vein anastomotic stenosis: correlation between ultrasound and transhepatic portal venography

The objective of this study was to determine which transabdominal ultrasound parameters correlate with portal vein stenosis (PVS) on percutaneous transhepatic portal venography in pediatric liver transplant patients. A retrospective review was performed of percutaneous transhepatic portal venograms performed between 2005 and 2013. The findings were compared to those from ultrasounds performed before venography and at the baseline. Patients were stratified on the basis of the presence of significant PVS (group 1, >50% stenosis; group 2, ≤50% stenosis) on portal venography. Findings were compared to those for age-matched controls. Twenty portal venograms were performed for 12 pediatric patients. Thirteen of the 20 patients (65%) demonstrated significant PVS (>50%). The mean peak anastomotic velocity (PAV) was 253.6±96 cm/s in group 1, 169.7±48 cm/s in group 2, and 51.3±20 cm/s in the control group. PAV (r=0.672, P=0.002) was the only ultrasound variable that correlated with the presence of significant PVS. A receiver operating characteristic curve was generated from PAV and PVS data (area under the curve=0.75, P=0.08). A threshold velocity of 180 cm/s led to a sensitivity of 83% and a specificity of 71% in predicting significant PVS on portal venography. At the baseline, the mean PAV was 155.8±90 cm/s for group 1 and 69.5±33 cm/s for group 2 (P=0.08); for control subjects, it was 78.9±53 cm/s (P=0.06). PAV is the only measured ultrasound parameter that correlates with significant PVS on portal venography in pediatric liver transplant patients. An elevated baseline PAV may increase the risk of developing PVS.

Current state of the art in management of vascular complications after pediatric liver transplantation

Vascular complications by compromising the blood flow to the allograft can have significant and sometimes life-threatening consequences after pediatric liver transplantation. High level of suspicion and aggressive utilization of diagnostic modalities can lead to early diagnosis and salvage of the allograft. This review will summarize the current trends in management of vascular complications after pediatric liver transplantation.

Long-term outcome of percutaneous transhepatic balloon angioplasty for portal vein stenosis after pediatric living donor liver transplantation: a single institute's experience

PURPOSE

To evaluate retrospectively the long-term outcomes of percutaneous transhepatic balloon angioplasty performed for portal vein stenosis (PVS) after pediatric living donor liver transplantation (LDLT).

MATERIALS AND METHODS

Between October 1997 and December 2013, of 527 pediatric patients (age < 18 y) who underwent LDLT in a single institution, 43 patients (19 boys, 24 girls; mean age, 4.1 y ± 4.1) were confirmed to have PVS at direct portography with or without manometry and underwent percutaneous interventions, including balloon angioplasty with or without stent placement. Technical success, clinical success, laboratory findings, manometry findings, patency rates, and major complications were evaluated. Follow-up periods after initial balloon angioplasty ranged from 5-169 months (mean, 119 mo).

RESULTS

Technical success was achieved in 65 of 66 sessions (98.5%) and in 42 of 43 patients (97.7%), and clinical success was achieved in 37 of 43 patients (86.0%). Platelet counts improved significantly. Of 32 patients undergoing manometry, 19 showed significant improvement of pressure gradient across the stenosis after percutaneous transhepatic balloon angioplasty. At 1, 3, 5, and 10 years after balloon angioplasty, the rates of primary patency were 83%, 78%, 76%, and 70%, and the rates of primary-assisted patency were 100%, 100%, 100%, and 96%. Two major complications subsequent to balloon angioplasty were noted: severe asthma attack and portal vein thrombosis.

CONCLUSIONS

Percutaneous transhepatic balloon angioplasty is a safe and effective treatment with long-term patency for PVS after pediatric LDLT.

A bidirectional approach for portal vein stent placement in a child with complete portal vein occlusion after living donor liver transplantation

Delayed PV complications are not rare in pediatric liver transplantation. Although PTPV offers a treatment and minimizes surgical revision, in case of complete PV thrombosis (PVT), the failure rate of PTPV is high. Herein, we report a successful technique of PTPV in a case of complete PVT with a stent placement using a bidirectional approach in a child with living donor liver transplantation.

Recanalization of post-transplant late-onset long segmental portal vein thrombosis with bidirectional transhepatic and transmesenteric approach

PV complications are the most frequent vascular complications in pediatric LT. We have experienced a case with chronic postoperative PVT that necessitates combined transhepatic and transmesenteric approach and have confirmed mid-term patency. An eight-yr-old boy had successful LDLT with a left lateral segment graft at the age of two months for HBV-related acute liver failure. Seven years after transplantation, the patient suddenly showed a melena with hypovolemic shock. Doppler ultrasound and CT revealed intrahepatic bile duct dilatation and main PVT with collateral formation at hepatic hilus and mesenterium of the Roux-en-Y jejunal loop. Urgent splenic artery embolization was performed to control the bleeding and was temporarily effective. Therefore, recanalization of PVO was attempted. Because of long segmental PVO and steep angle between the intrahepatic PV and the portal trunk, bidirectional transhepatic and transmesenteric approach was selected and resulted in deploying three metallic stents necessitating additional infusion thrombolytic therapy. The patient is now followed as an outpatient with patent stents for two yr since the procedure. For the rescue of these patients, recanalization of obstructed PV trunk with bidirectional approach would be feasible with better graft survival and less invasiveness than conventional surgical interventions.

Long-term results of the percutaneous transhepatic venoplasty of portal vein stenoses after pediatric liver transplantation

  This paper has the objective to evaluate retrospectively the long-term results of transhepatic treatment of PV stenoses after pediatric LT. During an eight-yr period, 15 children with PV stenoses underwent PTA with balloon dilation or stent placement in case of PTA failure after LT. Patients' body weights ranged from 9.3 to 46kg (mean, 15.5kg). PV patency was evaluated in the balloon dilation and in the stent placement groups. Technical and clinical successes were achieved in all cases with no complication. Eleven patients (11/15; 73.3%) were successfully treated by single balloon dilation. Four patients (4/15; 26.7%) needed stent placement. One patient was submitted to stent placement during the same procedure because of PTA failure. The other three developed clinical signs of portal hypertension because of PV restenoses two, eight, and twenty-eight months after the first PTA. They had to be submitted to a new procedure with stent placement. The follow-up time ranged from 3 to 8.1 yr (mean, 6.3 yr). In conclusion, transhepatic treatment of PV stenoses after pediatric LT with balloon dilation or stent placement demonstrated to be a safe and effective treatment that results in long-term patency.

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.

Pediatric liver transplantation: A report from a pediatric surgical unit

BACKGROUND

Liver transplantation is well established worldwide as an effective treatment for end-stage liver disease in children. Acceptance in India has been slow because of considerations of cost, infections, inability to support long-term care, and non-availability of expertise.

AIM

This study was designed to report our experience with pediatric liver transplantation.

MATERIALS AND METHODS

Twenty-eight children underwent liver transplantation.

RESULTS

Biliary atresia was the commonest indication (n = 15) followed by metabolic liver disease. Twenty-six children had living donor transplants, mothers being the donors in a majority of these. Common surgical complications included bile leaks (n = 3) and vascular problems (n = 6). Common medical complications included infections, acute rejection, and renal failure. Overall, patient survival was 71%, while that for the last 14 cases was 92%. All survivors are doing well, have caught up with physical and developmental milestones and are engaged in age appropriate activities.

CONCLUSIONS

The study demonstrates the feasibility of a successful pediatric liver transplant program in our country.

Balloon-occluded retrograde transvenous obliteration for a portosystemic shunt after pediatric living-donor liver transplantation

Portosystemic shunts may cause steal phenomenon after liver transplantation, which can lead to graft loss without proper management. Portal vein stenosis is one of the causes for the occurrence of portosystemic shunts after liver transplantation. Recently, new interventional radiologic techniques have been developed in the field of liver transplantation. Balloon-occluded retrograde transvenous obliteration (B-RTO) is a novel interventional technique for gastric varices and portosystemic shunts and also is effective for increasing portal vein flow. We herein report a pediatric case of portal vein stenosis with a large shunt successfully treated with a combination of balloon dilatation and B-RTO. If enlarged collateral vessels cause steal phenomenon, then B-RTO should be considered as an additional therapy.

Portal vein obstruction after liver transplantation in children treated by simultaneous minilaparotomy and transhepatic approaches: initial experience

Portal vein thrombosis is a complication that occurs anytime after liver transplantation and can compromise the patient and graft survival. We describe a combined technique for PV recanalization in cases of PV obstruction after liver transplantation. Four children (1%), of 367 subjected to liver transplantation from June 1991 to December 2008, underwent PV recanalization through a combined approach (transhepatic and minilaparotomy). All children received left lateral hepatic segments, developed Portal vein thrombosis (n=3) and stenosis (n=1), and presented with symptoms of portal hypertension after transplantation. PV recanalization was tried by transhepatic retrograde access, and a minilaparotomy was performed when percutaneous recanalization was unsuccessful. Three patients underwent a successful portal recanalization and stent placement with the combined technique. In one patient, the recanalization was unsuccessful because of an extensive portomesenteric thrombosis. The other three children had the portal flow reestablished and followed with Doppler US studies. They received oral anticoagulation for three consecutive months after the procedure and the clinical symptoms subsided. In case of PV obstruction, the combined approach is technically feasible with good clinical and hemodynamic results. It' is a minimally invasive procedure and can be tried to avoid or delay surgical treatment or retransplantation.

Can Doppler sonography discern between hemodynamically significant and insignificant portal vein stenosis after adult liver transplantation?

OBJECTIVE

The purpose of our study was to determine whether Doppler sonography, using a strict reference standard, can specifically identify hemodynamically significant portal vein anastomotic stenosis after liver transplantation in adults.

MATERIALS AND METHODS

The duplex and color Doppler examinations of 13 consecutive adult patients who underwent portal venography for suspected portal vein stenosis after liver transplantation were retrospectively examined. Peak systolic velocity (PSV) and change in PSV (ΔPSV) along the portal vein were correlated with portal venography. Stenoses above 50% on the basis of strict venographic criteria were considered hemodynamically significant. The Doppler studies before and after intervention were also assessed. Fourteen randomly chosen subjects with transplants without suspicion of portal anastomotic stenosis acted as controls.

RESULTS

Six patients had significant portal vein stenosis (> 50%) and seven had stenosis below 50%. PSV and ΔPSV were significantly greater for patients with > 50% stenosis in comparison with those with ≤ 50% stenosis and control subjects. Optimal threshold values for PSV and ΔPSV were 80 and 60 cm/s, respectively, with either value alone yielding sensitivity of 100% and specificity of 84% for significant stenosis. Threshold values also included cases of stenosis below 50%. Five of six patients with > 50% stenosis underwent stenting, with poststent PSV and ΔPSV significantly declining to match that of control subjects. Three of seven with stenosis below 50% had stents placed but no significant change in the Doppler examination.

CONCLUSION

Doppler threshold criteria reliably exclude those without posttransplantation portal vein stenosis and have high sensitivity for detecting portal stenosis. However, these criteria cannot discern the extent of stenosis.

Strategy to prevent recurrent portal vein stenosis following interventional radiology in pediatric liver transplantation

Portal vein complications after liver transplantation (LT) are serious complications that can lead to graft liver failure. Although the treatment of interventional radiology (IVR) by means of balloon dilatation for portal vein stenosis (PVS) after LT is an effective method, the high rate of recurrent PVS is an agonizing problem. Anticoagulant therapy for PVS is an important factor for preventing short-term recurrence following IVR, but no established regimen has been reported for the prevention of recurrent PVS following IVR. In our population of 197 pediatric patients who underwent living donor liver transplantation (LDLT), 22 patients (22/197, 11.2%) suffered PVS. In the 9 earliest patients, unfractionated heparin was the only anticoagulant therapy given following IVR. In the 13 more recent patients, 3-agent anticoagulant therapy using low-molecular-weight heparin, warfarin, and aspirin was employed. In the initial group of 9 patients, 5 patients (55.6%) suffered recurrent PVS and required repeat balloon dilatation. Among the 13 more recent patients, none experienced recurrent PVS (P = 0.002). In conclusion, our 3-agent anticoagulant therapy following IVR for PVS in pediatric LDLT can be an effective therapeutic strategy for preventing recurrent PVS.

[Mesenteric venous ischemia secondary to portal stenosis following liver transplantation]

We report a case of portal vein stenosis six months after previous orthotopic liver transplantation. The patient presented with mesenteric venous ischemia. He underwent successful percutaneous transhepatic portal vein angioplasty and stent placement.

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.

Diagnosis and treatment of pediatric patients with late-onset portal vein stenosis after living donor liver transplantation

Portal vein stenosis (PVS) after living donor liver transplantation (LDLT) is a serious complication that can lead to graft failure. Few studies of the diagnosis and treatment of late-onset (> or = 3 months after liver transplantation) PVS have been reported. One hundred thirty-three pediatric (median age 7.6 years, range 1.3-26.8 years) LDLT recipients were studied. The patients were followed by Doppler ultrasound (every 3 months) and multidetector helical computed tomography (once a year). Twelve patients were diagnosed with late-onset PVS 0.5-6.9 years after LDLT. All cases were successfully treated with balloon dilatation. Five cases required multiple treatments. Early diagnosis of late-onset PVS and interventional radiology therapy treatment may prevent graft loss.

Percutaneous portal venoplasty and stenting for anastomotic stenosis after liver transplantation

AIM: To review percutaneous transhepatic portal venoplasty and stenting (PTPVS) for portal vein anastomotic stenosis (PVAS) after liver transplantation (LT).

METHODS: From April 2004 to June 2008, 16 of 18 consecutive patients (11 male and 5 female; aged 17-66 years, mean age 40.4 years) underwent PTPVS for PVAS. PVAS occurred 2-10 mo after LT (mean 5.0 mo). Three asymptomatic patients were detected on routine screening color Doppler ultrasonography (CDUS). Fifteen patients who also had typical clinical signs of portal hypertension (PHT) were identified by contrast-enhanced computerized tomography (CT) or magnetic resonance imaging. All procedures were performed under local anesthesia. If there was a PVAS < 75%, the portal pressure was measured. Portal venoplasty was performed with an undersized balloon and slowly inflated. All stents were deployed immediately following the predilation. Follow-ups, including clinical course, stenosis recurrence and stent patency which were evaluated by CDUS and CT, were performed.

RESULTS: Technical success was achieved in all patients. No procedure-related complications occurred. Liver function was normalized gradually and the symptoms of PHT also improved following PTPVS. In 2 of 3 asymptomatic patients, portal venoplasty and stenting were not performed because of pressure gradients < 5 mmHg. They were observed with periodic CDUS or CT. PTPVS was performed in 16 patients. In 2 patients, the mean pressure gradients decreased from 15.5 mmHg to 3.0 mmHg. In the remaining 14 patients, a pressure gradient was not obtained because of > 75% stenosis and typical clinical signs of PHT. In a 51-year-old woman, who suffered from massive ascites and severe bilateral lower limb edema after secondary LT, PVAS complicated hepatic vein stenosis and inferior vena cava (IVC) stenosis. Before PTPVS, a self-expandable and a balloon-expandable metallic stent were deployed in the IVC and right hepatic vein respectively. The ascites and edema resolved gradually after treatment. The portosystemic collateral vessels resulting from PHT were visualized in 14 patients. Gastroesophageal varices became invisible on poststenting portography in 9 patients. In a 28-year-old man with hepatic encephalopathy, a pre-existing meso-caval shunt was detected due to visualization of IVC on portography. After stenting, contrast agents flowed mainly into IVC via the shunt and little flowed into the portal vein. A covered stent was deployed into the superior mesenteric vein to occlude the shunt. Portal hepatopetal flow was restored and the IVC became invisible. The patient recovered from hepatic encephalopathy. A balloon-expandable Palmaz stent was deployed into hepatic artery for anastomotic stenosis before PTPVS. Percutaneous transhepatic internal-external biliary drainage was performed in 2 patients with obstructive jaundice. Portal venous patency was maintained for 3.3-56.6 mo (mean 33.0 mo) and all patients remained asymptomatic.

CONCLUSION: With technical refinements, early detection and prompt treatment of complications, and advances in immunotherapy, excellent results can be achieved in LT.

Portal vein venoplasty and stent placement in the nontransplant population

PURPOSE

To review the technical success and results of attempted transcatheter management of portal vein (PV) stenosis and occlusion in the nontransplant population.

MATERIALS AND METHODS

All patients referred for percutaneous management of PV stenosis or occlusion between January 1997 and July 2007 were included in this review. Patients were included on an intent-to-treat basis, but liver transplant recipients were excluded. Intervention was attempted in 18 patients. Access to the portal system was achieved by the transhepatic route in 17 of 18 patients and by way of a preexisting transjugular intrahepatic portosystemic shunt in the other one. Indications for intervention included gastrointestinal bleeding (n = 8), ascites (n = 3), hemorrhage and ascites (n = 4), preoperative decompression of varices (n = 2), and intestinal angina (n = 1). Etiology of the PV stenosis or occlusion was postsurgical (n = 9), tumor encasement (n = 5), pancreatitis (n = 3), and unknown (n = 1).

RESULTS

Lesions were successfully crossed with a stent in 14 of 18 patients. Successful decompression of the portal system was achieved in 13 of 14. In one of 14 patients, the varices were not decompressed as a result of competitive flow. In four of 18 patients, the lesion could not be crossed. In the 13 technically successful cases in which the portal varices were decompressed, there was resolution of clinical symptoms with no immediate periprocedural complications.

CONCLUSIONS

PV stent placement is safe, with an acceptable success rate, and provides symptomatic relief from the sequelae of presinusoidal portal hypertension.

Midterm and long-term results of percutaneous endovascular treatment of venous outflow obstruction after pediatric liver transplantation

PURPOSE

To evaluate retrospectively the midterm and long-term results of percutaneous endovascular treatment of venous outflow obstruction after pediatric liver transplantation.

MATERIALS AND METHODS

During a 9-year period, 18 children with obstruction of a hepatic vein (HV) or inferior vena cava (IVC) anastomosis underwent percutaneous transluminal angioplasty (PTA) with balloon dilation or stent placement in case of PTA failure after liver transplantation. Patients' body weights ranged from 7.7 kg to 42.6 kg (mean, 18.8 kg +/- 9). Potential predictors of patency were compared between balloon dilation and stent placement groups.

RESULTS

Forty-two procedures were performed (range, 1-11 per patient; mean, 2). Technical and initial clinical success were achieved in all cases. Major complications included one case of pulmonary artery stent embolization and one case of hemothorax. Three children (25%) with HV obstruction were treated with PTA and nine (75%) were treated with stent placement. Three children with IVC obstruction (75%) were treated with PTA and one (25%) was treated with a stent. There were two children with simultaneous obstruction at the HV and IVC; one was treated with PTA and the other with a stent. Cases of isolated HV stenosis have a higher probability of patency with balloon-expandable stent treatment compared with balloon dilation (P < .05). Follow-up time ranged from 7 days to 9 years (mean, 42 months +/- 31), and the primary assisted patency rate was 100% when stent placement was performed among the first three procedures.

CONCLUSIONS

In cases of venous outflow obstruction resulting from HV and/or IVC lesions after pediatric liver transplantation, percutaneous endovascular treatment with balloon dilation or stent placement is a safe and effective alternative treatment that results in long-term patency.

Real-time and Doppler US after pediatric segmental liver transplantation : I. Portal vein stenosis

BACKGROUND

Accurate diagnosis of portal vein (PV) stenosis by real-time and color Doppler US (CD-US) after segmental liver transplantation in children can decrease morbidity by avoiding unnecessary biopsy, PV hypertension, thrombosis and loss of the graft.

OBJECTIVE

To evaluate CD-US parameters for the prediction of PV stenosis after segmental liver transplantation in children.

MATERIALS AND METHODS

We retrospectively reviewed 61 CD-US examinations measuring the diameter at the PV anastomosis, velocities at the anastomosis (PV1) and in the segment proximal to the anastomosis (PV2), and the PV1/PV2 velocity ratio. The study group comprised patients with stenosis confirmed by angiography and the control group comprised patients with a good clinical outcome.

RESULTS

PV stenosis was seen in 12 CD-US examinations. The mean PV diameter was smaller in the study group (2.6 mm versus 5.7 mm) and a PV diameter of <3.5 mm was highly predictive of stenosis (sensitivity 100%, specificity 91.8%).

CONCLUSION

A PV diameter of <3.5 mm is a highly predictive CD-US parameter for the detection of hemodynamically significant stenosis on angiography.

Transileocolic venous balloon dilatation for the management of primary and recurrent portal venous stenosis after living donor liver transplantation in children

Portal venous stenosis is relatively a rare complication after liver transplantation in children and it sometimes leads to life threatening event due to gastrointestinal bleeding or graft failure. Recently, balloon dilatation has been widely accepted as a treatment of choice for the management of portal venous stenosis. The purpose of this study was to evaluate the feasibility of transileocolic venous balloon dilatation for the management of primary and recurrent portal venous stenosis after living donor liver transplantation (LDLT) in children. The records of 57 pediatric liver transplants were retrospectively reviewed. Nine patients (15.8%) with portal venous stenosis were identified. Seven symptomatic children with portal venous stenosis underwent balloon dilatation. Two approaches were employed for balloon dilatation; the transileocolic venous approach and the percutaneous transhepatic approach. In patients with recurrent stenosis, careful follow-up was carried out while they were asymptomatic. Twelve balloon dilatations were performed in seven children with primary or recurrent portal venous stenoses. The initial technical success rate was 91.7% (11/12), while 6 out of 12 (50.0%) procedures resulted in recurrent stenosis. Five out of six recurrent stenoses required repeated balloon dilatation. The clinical success rate of balloon dilatation in our study was 85.7% (6/7). Other than recurrent stenosis, two procedure-related complications occurred. In conclusion, transileocolic venous balloon dilatation was a safe and effective procedure for portal venous stenosis after LDLT in children.

Intraoperative stent placement in the portal vein during or after liver transplantation

The purpose of this research was to evaluate the intermediate effectiveness of intraoperative portal vein stent placement for portal venous stenosis in liver transplantation. We attempted intraoperative portal vein stent placement in 44 portal venous anastomotic stenoses in 36 patients. All patients underwent stent placement via either the inferior or superior mesenteric vein. A total of 22 patients underwent portal vein stent placement simultaneously with liver transplantation, and 14 patients underwent stent placement 1-25 days (mean 5.93 days) after liver transplantation. Of the 22 patients, there was portal vein occlusion in 3 patients and small portal vein (<6 mm) in 10 patients (2.5-5.7 mm; mean size 3.9 mm). Patient follow-up included clinical and laboratory data collection, Doppler ultrasonography (US), and computed tomography (CT). Intraoperative portal vein stent placement was technically successful in all of our study patients, even in 6 patients with total occlusion of the portal vein. A total of 10 study patients underwent thrombectomy of the portal vein, 1 underwent patient portosystemic shunt ligation, and 7 patients had both procedures simultaneously. Portal venous patency has been maintained for 0-56 months (mean 16 months) in 42 (95%) of the 44 stent placements. In conclusion, intraoperative portal vein stent placement is an effective and long lasting treatment modality for treat portal venous stenosis, especially in patients with portal vein occlusion or small sized portal vein.

Vascular complications in living-related and deceased donation pediatric liver transplantation: single center's experience from Turkey

The aim of the study was to assess early and long-term incidence of venous complications, in both deceased donation (DD) and living-related (LR) liver transplantation (LT) in a pediatric population. Seventy-five liver transplants performed in 69 (39 boys, 30 girls) children at Ege University Hospital between 1997 and 2004 were prospectively monitored and reviewed. Age, sex, primary diagnosis, graft type, vascular complications and their management were evaluated. All patients received Doppler ultrasonographic examination both during operation and daily for the first three postoperative days and when necessary thereafter. The complications were classified as early and late presented. Thirty-three grafts (47.8%) were from DD and 36 (52.2%) were from LR donors. Recipients of DD were older than LR donors (mean age 10.5 +/- 5.1 and 5.0 +/- 0.7, respectively) (p < 0.05). Vascular complication occurrence was not statistically different between DDLT and LRLT recipients (p = 0.2), and between infants and children (p = 0.9). Overall, stenosis was more common than thrombosis. We observed hepatic artery (HA) thrombosis, in five of 75 (6.7%) transplants within 30 days post-transplant. Portal vein (PV) thrombosis and hepatic vein (HV) thrombosis were detected in six and one patients (8.7% and 1.3%), respectively. Six PV stenosis were identified (8.7%), while HA and HV-VC (vena cava) stenosis occurred in one and six patients (1.4% and 8.7%), respectively. All PV stenosis (6/33, 18.2%) and one PV aneurysm occurred in DDLT recipients while HV-VC stenosis were detected almost equally in LRLT and DDLT recipients (4/36 vs. 2/33). Except one, all PV stenosis were detected as a late complication and no intervention were needed. Stenosis of HV-VC was more common in girls (5/30 vs. 1/39) (p < 0.05) and the incidence was not different in DDLT and LRLT recipients (p = 0.8). In conclusion, overall incidences of thrombosis and stenosis formation after orthotopic liver transplantation (OLT) were 17.4% and 18.8%, respectively in our center. We suggest that in the cases with HA thrombosis manifested intra-operatively or within the early postoperative period, graft salvage was successful. Thrombosis of HA causes significant mortality. Thrombosis of PV was among the causes of mortality and morbidity. Stenosis of HV-VC could be managed by angioplasty and endovascular stenting with no significant effect to mortality.

Percutaneous intravascular stents for treatment of portal venous stenosis after liver transplantation: midterm results

Portal vein stenosis after liver transplantation is a relatively uncommon vascular complication that may result in graft loss if not promptly treated. The purpose of this study was to evaluate the midterm result of the use of intravascular stents for portal vein stenosis after liver transplantation. From April 2004 to September 2005, percutaneous transhepatic balloon dilation with stent deployment was performed in nine cases. Varices were embolized with stainless steel coils in two cases. No procedure-related complication occurred. Portal venous patency was maintained in all nine patients from 6 to 19 months (mean 10 months). In conclusion, an intravascular stent is an effective treatment for the portal vein stenosis after liver transplantation with excellent midterm patency.

Portal vein stenosis and occlusion stenting after liver transplantation in two adults

We report two cases of percutaneous transhepatic stenting of the portal vein to treat stenosis and occlusion disclosed 5 and 18 months, respectively, after orthotopic liver transplantation in two adult patients. If long-term patency is satisfactory, this technique should allow long-term management of portal vein stenosis and occlusion without the use of thrombolysis.

Endovascular Treatment of Acute Portal Vein Thrombosis After Liver Transplantation in a Child

Although operative techniques in hepatic transplantation have reduced the time and mortality on waiting lists, the rate of vascular complications associated with these techniques has increased. Stenosis or thrombosis of the portal vein is an infrequent complication, and if present, surgical treatment is considered the traditional management. This article describes a case of acute portal vein thrombosis after liver transplantation from a living donor to a child managed by percutaneous techniques.

Percutaneous angioplasty of portal vein stenosis that complicates liver transplantation: the mid-term therapeutic results

Objective

We wanted to valuate the mid-term therapeutic results of percutaneous transhepatic balloon angioplasty for portal vein stenosis after liver transplantation.

Materials and Methods

From May 1996 to Feb 2005, 420 patients underwent liver transplantation. Percutaneous transhepatic angioplasty of the portal vein was attempted in six patients. The patients presented with the clinical signs and symptoms of portal venous hypertension or they were identified by surveillance doppler ultrasonography. The preangioplasty and postangioplasty pressure gradients were recorded. The therapeutic results were monitored by the follow up of the clinical symptoms, the laboratory values, CT and ultrasonography.

Results

The overall technical success rate was 100%. The clinical success rate was 83% (5/6). A total of eight sessions of balloon angioplasty were performed in six patients. The mean pressure gradient decreased from 14.5 mmHg to 2.8 mmHg before and after treatment, respectively. The follow up periods ranged from three months to 64 months (mean period; 32 months). Portal venous patency was maintained in all six patients until the final follow up. Combined hepatic venous stenosis was seen in one patient who was treated with stent placement. One patient showed puncture tract bleeding, and this patient was treated with coil embolization of the right portal puncture tract via the left transhepatic portal venous approach.

Conclusion

Percutaneous transhepatic balloon angioplasty is an effective treatment for the portal vein stenosis that occurs after liver transplantation, and our results showed good mid-term patency with using this technique.

Hepatic venous reconstruction in pediatric living-related donor liver transplantation--experience of a single center

In pediatric patients submitted to living related liver transplantation, hepatic venous reconstruction is critical because of the diameter of the hepatic veins and the potential risk of twisting of the graft over the line of the anastomosis. The aim of the present study is to present our experience in hepatic venous reconstruction performed in pediatric living related donor liver transplantation. Fifty-four consecutive transplants were performed and two methods were utilized for the reconstruction of the hepatic vein: direct anastomosis of the orifice of the donor left or left and middle hepatic veins and the common orifice of the recipient left and middle hepatic veins (group 1-26 cases), and wide triangular anastomosis after creating a wide triangular orifice in the recipient inferior vena cava at the confluence of all the hepatic veins with an additional longitudinal incision in the inferior angle of the orifice (group 2-28 cases). In group 1, eight patients were excluded because of graft problems in the early postoperative period and five among the remaining 18 patients (27.7%) presented stricture at the site of the hepatic vein anastomosis. All these patients had to be submitted to two or three sessions of balloon dilatations of the anastomoses and in four of them a metal stent had to be placed. The liver histopathological changes were completely reversed by the placement of the stent. Among the 28 patients of the group 2, none of them presented hepatic vein stenosis (p = 0.01). The results of the present series lead to the conclusion that hepatic venous reconstruction in pediatric living donor liver transplantation must be preferentially performed by using a wide triangulation on the recipient inferior vena cava, including the orifices of the three hepatic veins. In cases of stenosis, the endovascular dilatation is the treatment of choice followed by stent placement in cases of recurrence.

MDCT imaging of post interventional liver: a pictorial essay

In this pictorial essay, we consider the post operative MDCT findings after liver resection, transplantation, surgical managed major trauma and radiofrequency ablation of focal lesions. Common complications such as fluid collections, hemorrhage, biloma, vascular disease, hematoma, abscesses will be also considered.

Vascular complications after living related liver transplantation: evaluation with gadolinium-enhanced three-dimensional MR angiography

OBJECTIVE

The purpose of this study was to evaluate the efficacy of gadolinium-enhanced three-dimensional (3D) MR angiography for detection of vascular complications in patients who have undergone living related liver transplantation.

MATERIALS AND METHODS

Seventy-six patients who underwent living related liver transplantation were evaluated with gadolinium-enhanced 3D MR angiography. All MR angiograms were assessed for patency of the hepatic artery and the portal vein using a four-point scale (grades I-IV). The results were correlated with conventional angiography (n = 23) and clinical follow-up with Doppler sonography (n = 53) for more than 6 months.

RESULTS

Seventy-three of 76 MR angiography procedures were technically adequate. When grades III (focal narrowing [> 50%] at the anastomotic site) and IV (abrupt cutoff at the anastomotic site with nonvisualization of the right [or left] hepatic artery distal to the anastomosis) were regarded as the diagnostic criteria for hepatic artery stenosis, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MR angiography were 100%, 74%, 29%, 100%, and 77%, respectively. In the portal vein, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MR angiography were 100%, 84%, 35%, 100%, and 85%, respectively, when grades III (narrowing [> 50%] without poststenotic dilatation) and IV (narrowing [> 50%] with poststenotic dilatation) were defined as criteria for portal vein stenosis.

CONCLUSION

MR angiography was sensitive but not specific in the detection of significant vascular stenosis after living related liver transplantation. However, normal MR angiography findings reliably exclude the possibility of significant stenosis.

Long-term venous complications after full-size and segmental pediatric liver transplantation

OBJECTIVE

To assess the long-term incidence of venous complications, including portal vein and hepatic vein stenoses, in both whole cadaveric and reduced-size cadaveric and living related liver transplants in a pediatric population, and to assess the therapeutic modalities in the treatment of these lesions.

SUMMARY BACKGROUND DATA

A shortage in appropriate-sized liver grafts for pediatric patients led to the use of segmental liver grafts, which became the predominant graft used in 325 of 600 (54%) transplants at the authors' institution. To assess the long-term impact of this strategy, the authors examined the incidence of late (>90 days) venous complications and the efficacy of all therapeutic interventions.

METHODS

Six hundred pediatric liver transplants were performed in 325 patients, with reduced-size or split (RSS; n = 207), living related (LRD; n = 118), or full-size cadaveric grafts (FS; n = 275) from 1988 to 2000. All transplants identified with late portal vein or vena caval stenoses or thromboses from a cohort of 524 grafts with survival greater than 90 days were reviewed for demographics, symptoms, therapeutic intervention, recurrence, morbidity, and mortality.

RESULTS

Fifty lesions were identified in 49 patients (38 portal vein and 12 hepatic vein-cava stenoses). Sex distribution was similar between portal vein and hepatic vein to cava, as was the mean patient age. Portal vein stenoses occurred in 32 LRD, 3 RSS, and 3 FS, while hepatic vein-cava stenoses occurred in 2 LRD, 8 RSS, and 2 FS. In the 38 portal vein stenoses, 9 had prior perioperative portal vein and/or 5 hepatic artery thrombectomies. Portal vein stenoses were identified after bleeding (17/38), ascites (6/38), increased liver function tests (6/38), splenomegaly (5/38), or screening ultrasound (4/38). Portal vein stenosis was associated most often with cryopreserved vein for portal conduits. Excluding conduits, the incidence of late portal vein complications was reduced to 1%. Lesions became symptomatic at a mean of 50.8 +/- 184.2 months posttransplant. All patients underwent venous angioplasty with a 66% (25/38) success rate, while 7 of 25 required further angioplasty and stenting. In the 13 unsuccessful angioplasties, 8 required surgical shunts for complete portal vein thrombosis. Recurrence occurred in 9 patients: all were amenable to stenting. Nine patients (24%) eventually died of sepsis (4) and surgical deaths at shunt or retransplant (5). Hepatic vein-cava stenoses occurred after a mean of 37.2 +/- 35.2 months, presenting with ascites (n = 10), increased liver function tests (n = 2), and splenomegaly (n = 2). All patients were diagnosed by venogram and managed by balloon dilatation alone (n = 6) or stented (n = 4), with an 80% (10/12) success, with two late recurrences amenable to repeat angioplasty or stenting. Long-term survival was 80% at 1 year.

CONCLUSIONS

The use of segmental grafts without venous conduits is not associated with a significant rate of long-term venous complication. When late venous complications do occur, venous angioplasty and stenting are both a safe and effective management modality. If necessary, venous angioplasty may be repeated with the placement of a stent. When this is required, care must be taken to place the stent in a position where the metallic object will not interfere with future surgical manipulations should retransplantation be necessary.

Interventional Radiology in the Pediatric Liver Transplant Patient

Liver transplantation now plays a major role in the treatment of end-stage liver disease in children. Reduced-size liver transplant surgical techniques have allowed increasing numbers of children to undergo liver transplantation. As more children are undergoing liver transplantation, there is a growing need for radiologic diagnosis of and intervention in post-transplantation complications in these patients.

Outcome of extra-anatomic vascular reconstruction in orthotopic liver transplantation

BACKGROUND

Portal venous and hepatic arterial reconstruction are critical to successful outcomes in orthotopic liver transplantation (OLT). With portal vein thrombosis or inadequate hepatic arterial inflow, extra-anatomic vascular reconstruction is required. However, the clinical outcomes following extra-anatomic vascular reconstruction are largely unknown.

METHODS

To determine the outcomes associated with extra-anatomic vascular reconstruction, we performed a retrospective review of 205 OLT recipients transplanted between 1995 and 2000.

RESULTS

Extra-anatomic portal venous inflow was based upon the recipient superior mesenteric vein using donor iliac vein graft in a retrogastric position (n = 12). Extra-anatomic arterial inflow was based on recipient infrarenal aorta using donor iliac artery graft through the transverse mesocolon (n = 25). OLT with routine anatomic vascular construction served as control (n = 168). Extra-anatomic vascular reconstruction was not associated with increased morbidity, mortality, operating room time, length of stay, or thrombosis.

CONCLUSION

We conclude that extra-anatomic vascular conduits are associated with excellent long-term outcomes and provide acceptable alternatives for vascular reconstruction in OLT.

Complicações vasculares pós-transplante hepático

OBJETIVO: O objetivo do estudo é apresentar as complicações vasculares arteriais e venosas observadas em um serviço de transplante hepático universitário brasileiro. MÉTODOS: Os prontuários de todos os pacientes submetidos a transplante hepático no período de setembro de 1991 a janeiro de 2000 foram analisados para determinar as complicações vasculares e correlacioná-las a dados clínicos e do procedimento cirúrgico. RESULTADOS: Foram realizados 169 transplantes, sendo quatro inter vivos e nove retransplantes. Um total de 24 complicações vasculares (14,3%) foi identificado em 22 pacientes (13,0%). A complicação vascular mais comum foi a trombose da artéria hepática (15 casos), seguido da trombose da veia porta (quatro casos). Complicações da veia cava inferior infra ou supra-hepática foram incomuns, ocorrendo em um total de três casos (1,8%). As complicações vasculares foram mais freqüentes nas crianças (26,06%) do que em adultos (13,14%) (p<0,05). Dos pacientes com trombose da artéria hepática, um foi submetido à angioplastia, um a trombectomia, oito a retransplante e cinco evoluíram para o óbito enquanto aguardavam retransplante. Dos quatro casos de trombose da veia porta, dois foram a óbito, um foi submetido à colocação percutânea de prótese e um a tratamento conservador. Os pacientes com estenose da veia porta e da veia cava inferior infra e supra-hepática foram submetidos a tratamento conservador, com boa evolução clínica. CONCLUSÕES: que as complicações vasculares são freqüentes após o transplante hepático, principalmente em crianças, e são associadas à elevada morbidade, mortalidade e retransplante.

Transjugular approach to treat portal vein stenosis after liver transplantation--a case report

The authors present a case of portal vein stenosis that developed shortly after liver transplantation in a 48-year-old woman treated successfully with portal stent implantation by use of a transjugular approach to achieve portal vein access. To their knowledge, there are no other reports in the literature on the use of a transjugular approach with vein stent placement in the treatment of portal stenosis complicating orthotopic liver transplantation.

Three-dimensional gadolinium-enhanced MR angiography of vascular complications after liver transplantation

OBJECTIVE

The goal of this study was to evaluate three-dimensional gadolinium-enhanced MR angiography as a tool for examination of liver transplant patients with potential vascular complications.

MATERIALS AND METHODS

Thirty-eight consecutive three-dimensional gadolinium-enhanced MR angiograms were obtained in 34 patients. Results were retrospectively reviewed and correlated with conventional angiography in 20 of the 38 cases and sonography in 37 of the 38 cases. MR angiograms were evaluated for technical adequacy, vascular patency, and parenchymal abnormalities, and results were compared with angiography and sonography. Conventional angiography and surgery were used as gold standards when available.

RESULTS

Thirty-four (90%) of 38 MR angiograms were technically adequate. Vascular abnormalities were identified in 20 patients, and 19 of these patients subsequently underwent angiography, surgery, or both. There were seven cases of hepatic artery thrombosis; all were detected with MR angiography with no false-positive or false-negative interpretations. Seven patients had moderate to severe hepatic artery stenosis (>50% narrowing as determined by conventional angiography). MR angiography revealed this stenosis in six of the seven patients, with one false-negative and three false-positive interpretations. Portal vein thrombosis was detected in three patients, and portal vein stenosis was detected in two patients.

CONCLUSION

Three-dimensional gadolinium-enhanced MR angiography is useful in the examination of liver transplant patients and offers a noninvasive adjunct in patients with difficult or indeterminate sonographic examinations.

Interstitial laser coagulation for hepatic tumours

BACKGROUND

The potential role of interstitial laser coagulation (ILC) for patients with irresectable hepatic tumours is currently being investigated. Since its introduction in 1983 it has evolved into an innovative minimally invasive technique.

METHODS

On the basis of a Medline literature search and the authors' experience, the principles, current state and prospects of ILC for hepatic tumours are reviewed.

RESULTS

Animal studies and early clinical studies have shown the safety and feasibility of ILC. The site of interest can be approached at laparoscopy or percutaneously and treatment is easily repeatable. Recent advances include the use of fibres with a cylindrical diffusing light-emitting tip, the length of which is adaptable to tumour diameter, water-cooled fibre systems, simultaneous multiple fibre application, and hepatic inflow occlusion during laser treatment. ILC allows complete destruction of tumours up to 5 cm in diameter. Currently a limitation is the lack of reliable real-time monitoring of laser-induced effects but progress in magnetic resonance imaging techniques should allow accurate temperature measurements to be obtained rapidly during treatment. However, the actual benefit of ILC in terms of patient survival remains to be investigated.

CONCLUSION

In terms of tools and experience, ILC has now been developed sufficiently to study its effect on survival of patients with irresectable hepatic tumours.

Portal vein thrombosis and stenosis in pediatric liver transplantation

The aim of this study was to determine the outcome of venous conduits used in living donor liver transplantation (LDLT). We analyzed the portal vein complications in 66 LDLT recipients and 48 cadaveric reduced-size liver transplant (RLT) recipients performed from November 1989 through January 1995. Three different venous conduits were utilized in the LDLT recipients: Group 1, reconstructed vein from the living donor, n=18; Group 2, cadaveric cryopreserved iliac vein, n=37; and Group 3, cadaveric cryopreserved femoral vein, n=11. Overall, 47 percent of the patients were less than one year of age; the age distribution was not significantly different among the groups. The incidence of early thrombosis was significantly greater in LDLT Group 1, (33%) than any of the other groups (LDLT Group 2, 8%; LDLT Group 3, 9%; and RLT, 4%:P<0.0005 vs. reduced graft and < 0.03 vs. other LDLT groups). The incidence of late portal vein stenosis or thrombosis was significantly higher in the LDLT Group 2, (51%) than any of the other groups (LDLT 1, 16%; LDLT Group 3, 9%; RLT 4%;P<0.005 vs. cadaveric and < 0.02 vs. LDLT Group 1 and LDLT Group 3). Five year arterial graft and patient survival for patients who have experienced portal vein thrombosis or stenosis is 61% and 67%, respectively, versus 67% and 71% for those patients who have not experienced portal vein pathology, P=ns. Based on this experience, we recommend avoiding the use of cryopreserved iliac vein for portal vein reconstruction in liver transplantation. Every effort should be taken to eliminate the need for venous conduits in liver transplantation. If venous conduits must be utilized, cryopreserved femoral veins seem to provide superior patency rates. Careful clinical and ultrasonopraphic monitoring of patients at high risk for late venous thrombosis permits therapy with excellent graft and patient survival.