Difficulty in sustaining hepatic outflow in left lobe but not right lobe living donor liver transplantation

Rescue of outflow block of the remnant left liver after extended right hemihepatectomy for resection of a tumor in the caudate lobe

Outflow block of the liver is a life-threatening event after living donor liver transplantation. Herein, we rescued a patient suffering from the outflow block of the remnant left hemiliver caused by bending of the left hepatic vein (LHV) after right hemihepatectomy plus caudate lobectomy combined with resection of the middle hepatic vein (MHV). A metastatic tumor sized 6 cm in the caudate lobe of the liver involving the root of the MHV was found in a 50's year old patient after resection of a right breast cancer eight years ago. Right hemihepatectomy and caudate lobectomy combined with resection of the MHV was performed using a two-stage hepatectomy (partial TIPE ALPPS). On day 1, the total bilirubin value increased to 4.5 mg/dL, and a dynamic computed tomography (CT) scan showed the bent LHV. On the diagnosis of outflow block of the left liver, a self-expandable metallic stent was placed in the LHV using an interventional approach, and the pressure in the LHV decreased from 27 cmH2O to 12 cmH2O. The bilirubin value decreased to 1.2 mg/dL on day 3. Outflow block of the LHV can happen after extended right hemihepatectomy with resection of the MHV. Early diagnosis and interventional stenting treatment can rescue the patient from congestive liver failure.

Diagnostic accuracy of CT and Doppler US for hepatic outflow obstruction after pediatric liver transplantation using left lobe or left lateral section grafts

PURPOSE

The aim of this study was to evaluate diagnostic accuracy and to establish computed tomography (CT) and Doppler ultrasonography (US) criteria for hepatic outflow obstruction after pediatric liver transplantation (LT) using left lobe (LL) or left lateral section (LLS) grafts.

METHODS

Pediatric patients who underwent LT using LL or LLS grafts between January 1999 and December 2021 were retrospectively included. The diagnostic performance of Doppler US and CT parameters for hepatic outflow obstruction was calculated using receiver operating characteristic (ROC) curve analysis. A diagnostic decision tree model combining the imaging parameters was developed.

RESULTS

In total, 288 patients (150 girls; median age at LT, 1.8 years [interquartile range, 0.9 to 3.6 years]) were included. Among the Doppler US parameters, venous pulsatility index (VPI) showed excellent diagnostic performance (area under the ROC curve [AUROC], 0.90; 95% confidence interval [CI], 0.86 to 0.93; Youden cut-off value, 0.40). Among the CT parameters, anastomotic site diameter (AUROC, 0.92; 95% CI, 0.88 to 0.95; Youden cut-off, 4.2 mm) and percentage of anastomotic site stenosis (AUROC, 0.88; 95% CI, 0.84 to 0.92; Youden cut-off, 35%) showed excellent and good diagnostic performance, respectively. A decision tree model combining the VPI, peak systolic velocity, and percentage of anastomotic site stenosis stratified patients according to the risk of hepatic outflow obstruction.

CONCLUSION

VPI, anastomotic site diameter, and percentage of anastomotic site stenosis were reliable imaging parameters for diagnosing hepatic outflow obstruction after pediatric LT using LL or LLS grafts.

Pediatric Hepatobiliary Interventions in the Setting of Intrahepatic Vascular Malformations, Portal Hypertension, and Liver Transplant

Within the broad spectrum of pediatric hepatobiliary disorders, hepatic vascular malformations, portal hypertension, and hepatic transplant interventions pose numerous challenges. The role of interventional radiology within each of these conditions is discussed herein, beginning with endovascular management of high flow hepatic vascular malformations. Next, while becoming less common in adult populations, surgical portoportal and portosystemic shunts remain prevalent in many pediatric centers. Shunt anatomy is reviewed along with endovascular management techniques for shunt dysfunction. Next, the growing experience with pediatric transjugular intrahepatic portosystemic shunt placement is reviewed along with tips for success in pediatric patients. Finally, pediatric hepatic transplant interventions are discussed with technical notes pertinent to split liver anatomy.

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.

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

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

Doppler ultrasound predictors of transplant hepatic venous outflow obstruction in pediatric patients

OBJECTIVE

To investigate Doppler US and catheter venogram correlates to improve detection of transplant HVOO and avoid unnecessary invasive imaging procedures.

MATERIALS AND METHODS

A retrospective review was performed in all pediatric OLT patients undergoing catheter venography of the hepatic veins between 2007 and 2017 at a single large tertiary pediatric liver transplant institution.

RESULTS

Forty-four transplant hepatic venograms in 32 OLT patients were included (mean 1.38, range 1-4 venograms per patient). All venograms were preceded by an independent Doppler US examination. Twenty-one (47.7%) venograms were performed for the investigation of suspected HVOO based on Doppler US alone, 19 (43.2%) were performed for TJLB without suspected HVOO, 4 (9.1%) were performed for both. Sixteen (36.3%) instances of >50% anastomotic stenosis were identified. Mean peak anastomotic velocities were 208 cm/s and 116 cm/s in the presence and absence of a >50% venographic stenosis, respectively (P < 0.004). In all cases where there was a monophasic waveform seen on Doppler US, there was a > 50% stenosis seen on hepatic vein venogram. In all cases where a triphasic waveform was seen on Doppler US, there was no stenosis seen on hepatic vein venogram.

CONCLUSION

While a Doppler US velocity threshold providing both high sensitivity and specificity has yet to be identified, increasing peak anastomotic velocity and decreasing intrahepatic venous velocity correlate strongly with venographic outflow stenosis. The presence of a triphasic intrahepatic waveform provides good NPV.

Novel use of percutaneous thrombosuction to rescue the early thrombosis of the conduit vein graft after living donor liver transplantation

A 54-year-old woman with liver cirrhosis and hepatocellular carcinoma received a living donor liver transplant. Thrombosis of the segmental hepatic vein occurred on postoperative day 7. We undertook percutaneous catheter thrombosuction under local anesthesia to extract the thrombus successfully without re-exploration. Thrombosuction has been used for thrombosis of the cardiovascular system, limbs, and brain. We first used it in hepatic venous thrombus after liver transplantation. This procedure is simple, less invasive, feasible, safe, repeatable, and effective.

Intraoperative Doppler sonogram in pediatric liver transplants: a pictorial review of intraoperative and early postoperative complications

A spectrum of vascular complications can be seen in pediatric liver transplant patients, including occlusion and hemodynamically significant narrowing of the vessels that provide inflow to or outflow from the graft. Intraoperative Doppler ultrasound (US) has the potential benefit of identifying vascular complications in pediatric liver transplant patients prior to abdominal closure. Importantly, intraoperative Doppler US can be used as a problem-solving tool in situations such as position-dependent kinking of the portal or hepatic veins, or in suspected vasospasm of the hepatic artery. Furthermore, this technique can be used for real-time reassessment after surgical correction of vascular complications. This pictorial review of intraoperative Doppler US in pediatric liver transplant patients illustrates normal findings and common vascular complications, including examples after surgical correction, in the perioperative period.

Outcomes of treatment with daclatasvir and asunaprevir for recurrent hepatitis C after liver transplantation

AIM

The development of direct-acting oral agents has dramatically changed the treatment strategy of hepatitis C virus (HCV) infection. Here we aimed to reveal the efficacy and safety of daclatasvir (DCV) and asunaprevir (ASV) for recurrent HCV genotype 1 infection after liver transplantation (LT).

METHODS

A retrospective study was undertaken on nine patients who underwent a 24-week DCV/ASV treatment regimen for recurrent HCV genotype 1 infection. Five of the patients were men; four had failed treatment with pegylated interferon (Peg-IFN)/ribavirin, two had failed simeprevir/Peg-IFN/ribavirin, one had the resistance-associated variant Y93H in the NS5A region, and one underwent maintenance dialysis.

RESULTS

Median time to treatment initiation following LT was 70 months. Of the nine patients treated with DCV/ASV, eight (88.9%) achieved a sustained viral response 12 weeks after completion of therapy (SVR12). The patient with virologic failure had failed simeprevir/Peg-interferon/ribavirin therapy 4 months before undergoing the DCV/ASV treatment regimen. In addition, a resistance-associated variant D168E in the NS3 region was detected in the patient after discontinuation of the DCV/ASV regimen. The trough level of tacrolimus tended to decrease, and renal function showed no significant changes during treatment. Adverse events occurred in two patients (22.2%), but no severe adverse events occurred during treatment.

CONCLUSIONS

The DCV/ASV regimen was well tolerated, resulting in high rates of sustained viral response 12 weeks after completion of therapy for LT patients with recurrent HCV genotype 1 infection.

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.

Anomalous hepatic vein anatomy of left lateral section grafts and customized unification venoplasty for pediatric living donor liver transplantation

In liver transplantation, a left lateral section (LLS) graft may have an unusual variant left hepatic vein (LHV) anatomy. This study was designed to analyze the incidence of unusual LHV variants and to determine technical methods for effective reconstruction in infant recipients weighing approximately 10 kg or less. The study comprised 3 parts: an LHV variation analysis, a simulation-based design for the technical modification of graft LHV venoplasty, and its clinical application. The LHV anatomy of 300 potential LLS graft donors was classified into 4 types according to the number and location of the hepatic vein openings: (1) a single opening (n = 218 or 72.7%); (2) 2 large adjacent openings (n = 29 or 9.7%); (3) 2 adjacent openings, 1 large and 1 small (n = 34 or 11.3%); and (4) 2 widely spaced openings (n = 19 or 6.3%). Types 2 and 3 required wedged unification venoplasty, and type 4 required additional vein interposition. In a series of 49 cases using LLS grafts, the graft hepatic vein complication rate was 4.5% at 3 years; stenting was necessary for 1 of the 36 type 1 LHV grafts (2.8%) and for 1 of the 13 type 2-4 LHV grafts (7.7%, P = 0.46). A customized interposition-wedged unification venoplasty technique for coping with type 4 vein variations was developed with a simulation-based approach, and it was successfully applied to a 10-month-old male infant receiving an LLS graft with a type 4 LHV. In conclusion, nearly all LHV variations can be effectively managed with customized unification venoplasty. These venoplasty techniques represent beneficial surgical options as part of graft standardization for hepatic vein reconstruction in pediatric living donor liver transplantation.

"Left at right" adult liver transplantation: the feasibility of heterotopic implantation of left liver graft

Left liver grafts have been widely utilized in adult liver transplantation (LT) and yielded acceptable results. However, the conventional orthotopic implantation of a left liver graft imposes the potential risk of perioperative vascular complications. We report herein an alternative modified technique for adult left liver LT and evaluate its feasibility in LT. In this study, 10 recipients had their left liver graft rotated 180°, and heterotopically implanted at the right subphrenic space, which we termed "left at right" liver transplantation (LAR-LT). The sequence of vascular and biliary reconstruction was performed as standard techniques, and no perioperative vascular complications related to LAR-LT were encountered. There were two mortalities in this series, one due to a small-for-size graft dysfunction and the other due to postoperative internal hemorrhage. Two recipients had biliary strictures that were successfully managed by percutaneous biliary dilatation and Roux-en-Y hepaticojejunostomy. The clinical characteristics and outcomes of patients undergoing LAR-LT were also compared with patients undergoing conventional orthotopic left liver LT (n = 14). Although the results showed no significant difference between the two groups, according to our experience, the satisfactory outcome and easier technical reconstruction suggest that the LAR-LT modification could be a feasible alternative to left liver LT.

Challenges and Outcome of Left-lobe Liver Transplants in Adult Living Donor Liver Transplants

Adult-to-adult living donor liver transplant (LDLT) frequently depend on using the right-lobes of the donor for obtaining adequate graft-to-recipient weight ratio (GRWR) of over 0.8% in the recipient. However, left-lobes remain an important option in adults, since the morbidity in the donor is considerably less with left donor hepatectomy when compared with right side liver resection. Further benefits of left-lobes in LDLT include more predictable anatomy of the left hepatic duct and left portal vein, which are usually long and single resulting in easier anastomosis in the recipient. Likewise, left-lobe grafts are easier to implant with an excellent venous outflow through the combined orifice of left and middle hepatic vein, as opposed to the complex hepatic vein reconstruction required in right-lobe grafts. However, left hepatic artery is often multiple unlike the right hepatic artery. The holy grail of left-lobe transplants is avoidance of small for size syndrome (SFSS) in the recipients. The strategies for overcoming SFSS currently depend on circumventing portal hyperperfusion in the graft. Measurement of portal pressure and modulating it if high, by splenic artery ligation, splenectomy, or hemiportocaval shunts are proving successful in avoiding SFSS. The future aim in adult LDLT should be to use the left-lobe as much as possible for the benefit of the donor at the same time avoiding SFSS even at very low GRWR for the benefit of the recipient.

Standard hepatic vein reconstruction with patch plasty using the native portal vein in adult living donor liver transplantation

An outflow obstruction of the hepatic vein is a critical complication after living donor liver transplantation (LDLT) and occasionally leads to hepatic failure. Here we introduce a simple method for preventing outflow obstructions by patch plasty in adult LDLT. Between September 2001 and May 2010, 468 adult LDLT procedures were performed at Kyoto University Hospital. We harvested each recipient's portal vein (PV) from the extirpated liver for a patch. We intended to re-form several orifices of the hepatic veins into a single, large orifice. The patch was attached to the anterior wall of the re-formed orifice on the bench. After we put in the liver graft, the procedure for the hepatic vein anastomosis to the inferior vena cava was simple enough that the warm ischemia time was reduced. Three of the 468 cases were diagnosed with an outflow obstruction. All 3 cases underwent hepatic vein reconstruction without patch plasty. In contrast, none of the 159 cases that underwent LDLT with patch plasty suffered from an outflow obstruction, regardless of the liver graft type. The procedure for hepatic vein plasty using a patch from the native PV is simple and elegant and results in excellent outcomes. We propose this as the standard procedure for hepatic vein reconstruction in adult LDLT.