Obstructing Spontaneous Major Shunt Vessels is Mandatory to Keep Adequate Portal Inflow in Living-Donor Liver Transplantation

What Are Risk Factors for Graft Loss in Patients Who Underwent Simultaneous Splenectomy During Living-donor Liver Transplantation?

BACKGROUND

The consensus that portal venous pressure modulation, including splenectomy (Spx), prevents portal hypertension-related complications after living-donor liver transplantation (LDLT) has been established. However, little evidence about the risk factors for graft loss after simultaneous Spx during LDLT is available. This study aimed to identify the independent predictors of graft loss after simultaneous Spx during LDLT.

METHODS

Data of 655 recipients who underwent LDLT between 1997 and 2021 were collected and separated into the simultaneous Spx group (n = 461) and no-Spx group (n = 194).

RESULTS

The simultaneous Spx group had significantly lower serum total bilirubin levels, drained ascites volumes, and prothrombin time-international normalized ratios on postoperative day 14 than the no-Spx group ( P  < 0.001 for each). Incidences of small-for-size graft syndrome ( P  < 0.001), acute cellular rejection ( P  = 0.002), and sepsis ( P  = 0.007) were significantly lower in the Spx group. Graft survival of the Spx group was significantly better than that of the no-Spx group ( P  < 0.001; hazard ratio [HR], 1.788; 95% confidence interval, 1.214-2.431). A multivariate analysis revealed that 3 variables, platelet count ≤4.0 × 10 4 /mm 3 ( P  = 0.029; HR, 2.873), donor age ≥60 y old ( P  = 0.013; HR, 6.693), and portal venous pressure at closure ≥20 mm Hg ( P  = 0.010; HR, 3.891), were independent predictors of graft loss within 6 mo after simultaneous Spx during LDLT.

CONCLUSIONS

Spx is a safe inflow modulation procedure with a positive impact on both postoperative complications and prognosis for most patients. However, patients with the 3 aforementioned independent factors could experience graft loss after LDLT.

Imaging and Intervention in the Management of Vascular Complications Following Liver Transplantation

Liver transplantation is the treatment of choice in majority of the patients with end stage liver disease. Vascular complication following liver transplantation is seen in around 7-13% of the patients and is associated with graft dysfunction and high morbidity and mortality. Early diagnosis and prompt treatment are crucial in management of these patients. Advances in interventional radiology have significantly improved the management of vascular complications using minimally invasive percutaneous approach. Endovascular management is preferred in patients with late hepatic artery thrombosis, or stenosis, whereas retransplantation, surgical revision, or endovascular management can be considered in patients with early hepatic artery thrombosis or stenosis. Hepatic artery pseudoaneurysm, arterioportal fistula, and splenic artery steal syndrome are often treated by endovascular means. Endovascular management is also preferred in patients with symptomatic portal vein stenosis, early portal vein thrombosis, and symptomatic late portal vein thrombosis, whereas surgical revision or retransplantation is preferred in patients with perioperative portal vein thrombosis occurring within 3 days of transplantation. Venoplasty with or without stent placement can be considered in patients with hepatic venous outflow tract or inferior vena cava obstruction. Transjugular intrahepatic portosystemic shunt (TIPS) may be required in transplant recipients who develop cirrhosis, often, secondary to disease recurrence, or chronic rejection. Indications for TIPS remain same in the transplant patients; however, major difference is altered vascular anatomy, for which adjunct techniques may be required to create TIPS.

Treatment of refractory hepatic encephalopathy induced by spontaneous portosystemic shunt: Selective splenic vein embolization versus shunt embolization

BACKGROUND AND AIMS

Spontaneous portosystemic shunt (SPSS) can cause refractory hepatic encephalopathy (HE) in cirrhotic patients. The embolization of the shunt (ES) can resolve the HE, while the selective embolization of the splenic vein (SESV) can treat splenorenal shunts related HE. The aim of this study was to compare the clinical outcomes of ES and SESV when applied for the treatment of SPSS-induced refractory HE in cirrhotic patients.

METHODS

Patients with refractory HE who were treated with ES or SESV were retrospectively identified. The clinical outcomes were compared and analyzed.

RESULTS

The 6-month mortality after the ES procedure was significantly higher than that after the SESV procedure. During the 6-month follow-up, both the white blood cell and the platelet counts were significantly lower after the ES procedure than after the SESV procedure. There was a significant increase in aspartate aminotransferase levels after ES. However, the albumin levels as well as the Child-Pugh score and grade were found to be significantly improved at 6 months after the undertaking of an SESV (as compared with baseline).

CONCLUSION

The 6-month mortality was improved after SESV (as compared with ES) in the treatment of SPSS-induced refractory HE. A prospective multicenter study for validation is warranted.

Identification of reversed portal flow on 4DCT and of factors contributing to reversed portal flow in patients with liver cirrhosis and portosystemic shunt before interventional radiology procedures

AIM

Patients with liver cirrhosis and portosystemic shunt occasionally develop reversed portal flow in the portal venous system. The factors contributing to reversed portal flow in these patients remain unclear. The aim of this study was to identify factors contributing to reversed portal flow in patients with portosystemic shunts based on four-dimensional computed tomography (4DCT), which visualized flow dynamics in the portal venous system.

METHODS

Data from 34 consecutive patients with portosystemic shunts who had undergone 4DCT before interventional radiology procedures were retrospectively investigated in this study. Uni- and multivariate analyses were performed to identify factors contributing to reversed portal flow.

RESULTS

Flow dynamics could be visualized on 4DCT in 32 of the 34 patients. Fifteen patients had forward portal flow; 17 had reversed portal flow. The main portal, splenic, and superior mesenteric veins displayed reversed portal flow in five, 12, and five vessels, respectively. Portosystemic shunt originating from splenic and superior mesenteric veins, worse albumin-bilirubin score, and small main portal vein diameter were significant factors contributing to reversed portal flow in both univariate (p = 0.049, p = 0.027, and p = 0.002) and multivariate (odds ratio [OR] 6.345, p = 0.012; OR 4.279, p = 0.039; and OR 5.516, p = 0.019) analyses.

CONCLUSIONS

The reversed portal flow was visualized on 4DCT. Portosystemic shunt originating distant to the liver, worse albumin-bilirubin score, and small diameter of the main portal vein were factors contributing to reversed flow in the portal venous system.

Short-Term Results of Plug-Assisted Retrograde Transvenous Obliteration for Portal Steal from Complicated Portosystemic Shunts in Living-Donor Liver Transplantation

PURPOSE

To investigate the effectiveness of plug-assisted retrograde transvenous obliteration (PARTO) for portal steal from complicated portosystemic shunts (PSSs) in living-donor liver transplantation (LDLT).

MATERIALS AND METHODS

This retrospective study included consecutive patients who underwent LDLT and intraoperative or postoperative PARTO for complicated PSS between January 2020 and December 2021. PARTO was performed when hepatofugal portal flow steal was identified during intraoperative cineportography, and afferent vein embolization was difficult because of multiple afferent veins or incomplete afferent vein embolization. Liver volume, complete obliteration of PSS, technical success, adverse events, and follow-up clinical and laboratory data were evaluated.

RESULTS

Thirty-seven patients were included, and the technical success rate was 100% with no major adverse events. During the median follow-up of 20.0 months, all patients recovered well with suitable regeneration of the liver without graft dysfunction related to a portal steal. The liver volume significantly increased within 1 month (median, 956 vs 1,198 mL; P < .001). Complete obliteration of a PSS occurred in 36 of 37 (97.3%) patients, and there was no recurrence during follow-up. The Child-Pugh score, serum albumin and total bilirubin levels, and prothrombin time showed significant improvement over serial follow-up. Compared with preprocedural values (14.9 cm/s), follow-up portal flow (median) peaked on the first day (71.2 cm/s, P < .001) and then remained significantly high at 1 week (60.3 cm/s, P < .001) and 1 month (53.1 cm/s, P < .001), in accordance with the graft regeneration.

CONCLUSIONS

PARTO is an effective procedure for the treatment of complicated PSS in LDLT.

Hemodynamic alterations with large spontaneous splenorenal shunt ligation during adult deceased donor liver transplantation

Background

A large spontaneous splenorenal shunt (SRS) will greatly impact portal inflow to the graft during liver transplantation (LT). Direct ligation of a large SRS is an uncommon surgical procedure and the hemodynamic consequences of this procedure are unknown.

Methods

In this retrospective study, we described our technique for direct ligation of a large SRS and the consequent hemodynamic changes during LT. 3-Dimensional computed tomography and Doppler ultrasonography were used to evaluate SRS and portal vein blood flow volume (PFV).

Results

A total of 22 recipients had large SRS including 13 with PFV <85 ml/min/100 g (ligation group) and 9 with PFV ≥85 ml/min/100 g (no ligation group). The diameter of SRS was significantly larger in the ligation group than in the non-ligation group (22.92 ± 4.18 vs. 16.24 ± 3.60 mm; p = 0.0009). In all ligation patients, the SRS was easily identified and isolated, it was located just below the distal pancreas and beside the inferior mesenteric vein. PV flow increased significantly from 68.74 ± 8.77 to 116.80 ± 16.50 ml/min/100 g (p < 0.0001) after ligation; this was followed by a reduction in peak systolic velocity of the hepatic artery from 58.17 ± 14.87 to 46.67 ± 13.28 cm/s (p = 0.0013).

Conclusions

Direct ligation of large SRS was an effective and safe surgical procedure to overcome the problem of portal hypoperfusion during LT.

Caution for living donor liver transplantation with congenital portosystemic shunt: a case report

Background

Congenital portosystemic shunt is an infrequent abnormal connection between the portal vascular system and the systemic circulation. Portosystemic shunts are common findings in patients with cirrhosis, causing gastroesophageal varices, hepatic encephalopathy, and others. However, there is no consensus or literature describing how to manage asymptomatic patients with portosystemic shunts and normal liver.

Case presentation

The patient was a 39-year-old female who underwent donor right hepatectomy for living donor liver transplantation. The patient was healthy by nature, however, developed hepatic encephalopathy after the surgery due to a development of portosystemic shunt. Portosystemic shunt stole portal blood flow, and imaging modalities revealed narrowing of the portal trunk, representing prolonged depletion of portal blood flow. Balloon-occluded retrograde transvenous obliteration (B-RTO) was performed for occlusion of the portosystemic shunt. B-RTO increased portal blood flow, and hepatic encephalopathy with hyperammonemia was successfully resolved without the outbreak of any other symptom of portal hypertension.

Conclusions

A congenital portosystemic shunt itself is not a contraindication for donor hepatectomy, but perioperative endovascular shunts occlusion or intraoperative ligature of these shunts should be considered.

Management of spontaneous portosystemic shunts at the time of liver transplantation: treatment or observation? Results of a systematic review

BACKGROUND

Optimal treatment of spontaneous portosystemic shunts (SPSS) during liver transplantation (LT) remains debated. We systematically reviewed the literature on definitions, treatment and outcomes of patients presenting SPSS undergoing LT.

METHODS

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we used PubMed to retrieve all studies dealing with SPSS and LT between January 1987 and January 2020. The primary endpoints were definitions and outcomes according to the management of SPSS (treatment vs observation).

RESULTS

Thirteen studies detailing the management of 962 SPSS were retrieved. Hemodynamically significant SPSS were defined as those having diameter ≥ 10 mm in 41% (n = 395) of patients. SPSS were splenorenal (42%), cavo-gastric (15.2%), umbilical (7.4%), mesenterico-caval (n = 31; 3.2%), mesenterico-renal (0.1%) and unreported (31.9%), respectively. At the time of LT 372 shunts (38.7%) were treated while 590 were observed (61.3%). During a follow-up time ranging from 4 months to 5 years, the reported overall survival (OS) at 1 year was not significantly different except for one study. Portal vein anastomosis complications (i.e. reduced flow, stenosis or thrombosis) were similarly reported in observed [n = 26 (4%)] and ligated SPSS [n = 10 (2%)] (p = 0.22) but the rate of relaparotomy was significantly higher in observed SPPS (16 vs 2; p = 0.01) to rescue post LT portal vein thrombosis (n = 6) and reduced portal flow and graft dysfunction (n = 10).

CONCLUSIONS

There was a heterogeneous management of SPSS during LT in the literature. Ligation of SPPS did not reduce vascular complications neither improved survival. A randomized prospective study might contribute to identify best management of SPSS at time of LT.

Small-For-Size Syndrome and Graft Inflow Modulation Techniques in Liver Transplantation

BACKGROUND

Partial liver transplantation has recently been proposed to alleviate organ shortages. However, transplantation of a small-for-size graft is associated with an increased risk of posttransplant hepatic dysfunction, commonly referred to as small-for-size syndrome (SFSS). This review describes the etiology, pathological features, clinical manifestations, and diagnostic criteria of SFSS. Moreover, we summarize strategies to improve graft function, focusing on graft inflow modulation techniques. Finally, unmet needs and future perspectives are discussed.

SUMMARY

In fact, posttransplant SFSS can be attributed to various factors such as preoperative status of the recipients, surgical techniques, donor age, and graft quality, except for graft size. With targeted improvement measures, satisfactory clinical outcomes can be achieved in recipients at increased risk of SFSS. Given the critical role of relative portal hyperperfusion in the pathogenesis of SFSS, various pharmacological and surgical treatments have been established to reduce or partially divert excessive portal inflow, and recipients will benefit from individualized therapeutic regimens after careful evaluation of benefits against potential risks. However, there remain unmet needs for further research into different aspects of SFSS to better understand the correlation between portal hemodynamics and patient outcomes.

KEY MESSAGES

Contemporary transplant surgeons should consider various donor and recipient factors and develop case-specific prevention and treatment strategies to improve graft and recipient survival rates.

Augmentation Patch V-venoplasty to Correct Atretic Changes of the Portal Vein During Adult Liver Transplantation

The development of large spontaneous portosystemic shunts (PSS) is a common finding in liver cirrhosis. The diversion of the portal flow through PSS directly into the caval system causes progressive liver atrophy and atretic changes of the portal vein. During both living and deceased donor liver transplantation (LT), persistence of large PSS has been associated to portal flow steal phenomena causing decreased patients and graft survival. Atretic changes of the portal vein and large PSS often coexist potentially representing a technical challenge during portal vein reconstruction. We herein describe (with a didactical video) an easy augmentation patch V-venoplasty used in the presence of atretic changes of the portal vein LT.

Impact of spontaneous splenorenal shunt on liver volume and long-term survival of liver cirrhosis

BACKGROUND AND AIM

Spontaneous splenorenal shunt (SSRS) is one of the manifestations of portal hypertension in liver cirrhosis. However, the impact of SSRS on long-term survival of cirrhotic patients remains unclear. We hypothesize that SSRS may worsen liver dysfunction and deteriorate prognosis in liver cirrhosis by decreasing hepatic perfusion.

METHODS

Patients with liver cirrhosis who were admitted to our department between December 2014 and August 2019 and underwent contrast-enhanced computed tomography or magnetic resonance imaging scans were prospectively collected. The maximum diameters of SSRS and portal vein system vessels were retrospectively measured. Liver-to-abdominal area ratio, Child-Pugh, and model for end-stage liver disease scores were calculated.

RESULTS

Overall, 122 cirrhotic patients were included. The prevalence of SSRS was 30.3% (37/122). Median diameter of SSRS was 13.5 mm. Patients with SSRS had significantly thinner diameters of right portal vein (9 mm vs 11.2 mm, P = 0.001) and main portal vein (15.3 mm vs 16.8 mm, P = 0.017) than those without SSRS. Patients with SSRS had significantly lower liver-to-abdominal area ratio score (25.39 vs 31.58, P < 0.001) and higher Child-Pugh (7 vs 6, P = 0.046) and model for end-stage liver disease (12.17 vs 9.79, P < 0.006) scores than those without SSRS. Patients with SSRS had a significantly lower cumulative survival rate than those without SSRS (P = 0.014). Cox regression analysis also showed that SSRS was a risk factor of death of cirrhotic patients (hazard ratio = 4.161, 95% confidence interval = 1.215-14.255, P = 0.023).

CONCLUSIONS

Spontaneous splenorenal shunt may narrow portal vein diameter and shrink liver volume, thereby worsening liver function and increasing mortality in liver cirrhosis.

Which is better to use "body weight" or "standard liver weight", for predicting small-for-size graft syndrome after living donor liver transplantation?

AIM

Little evidence about whether to apply graft-to-recipient body weight ratio (GRWR) or graft weight to standard liver weight (GW/SLW) for graft selection has been published. The aim of the present study was to clarify the importance of the correct use of GRWR and GW/SLW for selecting graft according to the recipients' physique in living donor liver transplantation (LDLT).

METHODS

Data were collected for 694 recipients who underwent LDLT between 1997 and 2020.

RESULTS

One of the marginal grafts meeting GW/SLW ≥ 35% but GRWR < 0.7% has been used in more recipients with men and higher body mass index (BMI), and the other meeting GRWR ≥ 0.7% but GW/SLW < 35% has been used in more recipients with women with lower BMI. In the cohort of BMI > 30 kg/m2, the recipients with GRWR < 0.7% had a significantly higher incidence of small-for-size graft syndrome (SFSS) compared to those with GRWR ≥ 0.7% (P = 0.008, 46.2% vs 5.9%), and using the cutoff of GW/SLW < 35% could not differentiate. In contrast, in the cohort of BMI ≤ 30 kg/m2, the recipients with GW/SLW < 35% also had a significantly higher incidence of SFSS (P = 0.013, 16.9% vs 9.4%). Multivariate analysis showed that GRWR < 0.7% [odds ratio (OR) 14.145, P = 0.048] was the independent risk factor for SFSS in obese recipients, and GW/SLW < 35% [OR 2.685, P = 0.002] was the independent risk factor in non-obese recipients.

CONCLUSION

Proper use of the formulas for calculating GRWR and GW/SLW in choosing graft according to recipient BMI is important, not only to meet metabolic demand for avoiding SFSS but also to ameliorate donor shortages.

The Significant Prognostic Factors in Prolonged Intensive/High Care Unit Stay After Living Donor Liver Transplantation

BACKGROUND

Prolonged stay in an intensive/high care unit (ICU/HCU) after living donor liver transplantation (LDLT) is a significant event with possible mortality.

METHODS

Adult-to-adult LDLTs (n = 283) were included in this study. Univariate and multivariate analyses were performed for the factors attributed to the prolonged ICU/HCU stay after LDLT.

RESULTS

Recipients who stayed in the ICU/HCU 9 days or longer were defined as the prolonged group. The prolonged group was older (P = .0010), had a higher model for end-stage liver disease scores (P < .0001), and had higher proportions of patients with preoperative hospitalization (P < .0001). Delirium (P < .0001), pulmonary complications (P < .0001), sepsis (P < .0001), reintubation or tracheostomy (P < .0001), relaparotomy due to bleeding (P = .0015) or other causes (P < .0001), and graft dysfunction (P < .0001) were associated with prolonged ICU/HCU stay. Only sepsis (P = .015) and graft dysfunction (P = .019) were associated with in-hospital mortality among patients with prolonged ICU/HCU stay or graft loss within 9 days of surgery. Among these patients, grafts from donors aged <42 years and with a graft-to-recipient weight ratio of >0.76% had significantly higher graft survival than grafts from others (P = .0013 and P < .0001, respectively).

CONCLUSION

Prolonged ICU/HCU stay after LDLT was associated with worse short-term outcomes. The use of grafts of sufficient volume from younger donors might improve graft survival.

Endovascular management of portal steal syndrome due to portosystemic shunts after living donor liver transplantation

Background and Aim

After liver transplant, pre‐existent porto‐systemic shunts (PSS) may persist, causing “portal steal,” leading to graft dysfunction, hepatic encephalopathy (HE), and eventual rejection. In recipients of small‐for‐size transplant liver grafts, shunts may be created intraoperatively, facilitating diversion of portal flow to systemic circulation to avoid ill‐effects of portal overperfusion. These iatrogenic shunts may also subsequently lead to portal steal. We aim to evaluate safety and efficacy of endovascular techniques in management of portal steal due to PSSs in living donor liver transplantation (LDLT) recipients.

Methods

Between 2013 and 2020, we encountered five LDLT recipients with large PSS, who presented with graft dysfunction and/or HE. One patient had a surgically created shunt and four had spontaneous shunts, not surgically ligated during transplant. Endovascular techniques including plug‐assisted or balloon‐occluded retrograde transvenous obliteration (PARTO/BRTO) or covered inferior vena cava (IVC) stent grafts were to occlude these PSS and counter the portal steal in all patients. Technical success and clinical outcomes at 1‐year‐follow‐up were assessed.

Results

Imaging showed large PSS causing portal steal syndrome in all five patients. IVC stent graft was used to isolate the shunt in two patients and PARTO/BARTO was performed in three patients. One patient had guarded prognosis due to multiple organ dysfunction and died 5 days after endovascular procedure. At 1‐year follow up, graft functions normalized in four patients with no recurrence of HE. No procedure‐related complications were seen.

Conclusion

Endovascular techniques can be safely and effectively used to counter portal steal syndrome in LDLT recipients, thus avoiding surgical re‐exploration in these patients.

Simultaneous splenectomy improves outcomes after adult living donor liver transplantation

BACKGROUND & AIMS

Small-for-size graft (SFSG) syndrome is a major cause of graft loss after living donor liver transplantation (LDLT). Splenectomy (Spx) is an option to prevent this catastrophic complication, but its effect remains controversial. Herein, we aimed to elucidate the effect of simultaneous Spx on graft function and long-term outcomes after LDLT.

METHODS

Three hundred and twenty patients were divided into 2 groups: those undergoing (n = 258) and those not undergoing (n = 62) simultaneous Spx. To overcome selection bias, propensity score matching (PSM) was performed (n = 50 in each group).

RESULTS

Before PSM, recipients undergoing simultaneous Spx showed better graft function on post-operative day (POD) 7 and 14, as well as lower sepsis frequency within 6 months after LDLT and better graft survival rates compared to those not undergoing Spx. After PSM, compared to patients not undergoing Spx, those undergoing Spx had a lower frequency of early graft dysfunction on POD 7 (p = 0.04); a lower frequency of SFSG syndrome (p = 0.01), lower serum total bilirubin levels (p = 0.001), and lower international normalized ratio (p = 0.004) on POD 14; lower sepsis frequency within 6 months after LDLT (p = 0.02), and better graft survival rates (p = 0.04). Univariate analysis revealed that not undergoing Spx (hazard ratio 3.06; 95% CI 1.07-11.0; p = 0.037) was the only risk factor for graft loss after LDLT.

CONCLUSIONS

Simultaneous Spx may prevent SFSG syndrome and is a predictive factor for graft survival after LDLT. Simultaneous Spx is recommended when a small graft (≤35% of standard liver weight) is predicted preoperatively, or for patients with portal hypertension or high portal pressure (above 20 mmHg) after reperfusion in LDLT.

LAY SUMMARY

Living donor liver transplantation (LDLT) for patients with acute or chronic liver failure is an alternative to overcome the deceased donor shortage. The potential mismatch between graft and body size is a problem that needs to be solved for LDLT recipients. Herein, we evaluated the impact of simultaneous splenectomy and showed that it was associated with favorable outcomes in patients undergoing LDLT.

Clinical Significance of Spontaneous Portosystemic Shunts in Living Donor Liver Transplantation

Spontaneous portosystemic shunts (SPSS) are commonly observed in patients undergoing living donor liver transplantation (LDLT); however, their impact on the outcome after transplantation is unclear. We aimed to assess the type, size, and the effects of SPSS on outcomes after LDLT. A total of 339 LDLT recipients in a single institution were included. The type and diameter of the SPSS (splenorenal shunt [SRS], oesogastric shunt, and umbilical shunt) were retrospectively analyzed. A large shunt was defined as having a diameter ≤7 mm. No portal flow modulation was attempted over time. Portal complications were defined as stenosis, thrombosis, or hepatofugal flow requiring any treatment after transplantation. There were 202 (59.0%) patients who exhibited at least 1 large SPSS. Neither the size nor type of SPSS was associated with mortality, morbidity, or liver function recovery. However, the incidence of portal complications was significantly higher in patients with a large SRS (8.6% versus 2.9%; P = 0.04). Multivariate analysis of portal complications revealed 2 independent predictors: pre-LT portal vein thrombosis (PVT) and SRS size. The observed risk among recipients with pre-LT PVT was 8.3% when the SRS was ≤7 mm, but increased to 38.5% when the SRS was >15 mm. The present study suggests that large SPSS do not negatively affect the outcomes after LDLT. However, a large SRS is associated with a higher risk of portal complications, particularly in recipients with pre-LT PVT, for whom intraoperative intervention for SRS should be considered. Otherwise, a conservative approach to SPSS during LDLT seems reasonable.

Small-for-size graft, small-for-size syndrome and inflow modulation in living donor liver transplantation

The extended application of living donor liver transplantation (LDLT) has revealed the problem of graft size mismatching called "small-for-size syndrome (SFSS)." The initial trials to resolve this problem involved increasing the procured graft size, from left to right, and even extending to include a right lobe graft. Clinical cases of living right lobe donations have been reported since then, drawing attention to the risks of increasing the liver volume procured from a living donor. However, not only other modes of increasing graft volume (GV) such as auxiliary or dual liver transplantation, but also control of the increased portal pressure caused by a small-for-size graft (SFSG), such as a porto-systemic shunt or splenectomy and optimal outflow reconstruction, have been trialed with some positive results. To establish an effective strategy for transplanting SFSG and preventing SFSS, it is essential to have precise knowledge and tactics to evaluate graft quality and GV, when performing these LDLTs with portal pressure control and good venous outflow. Thus, we reviewed the updated literature on the pathogenesis of and strategies for using SFSG.

Life-Threatening Portal Flow Steal Reappearing Under Increased Intrahepatic Vascular Resistance After Living Donor Liver Transplantation

Maintenance of adequate portal inflow is crucial for graft regeneration in adult living donor liver transplantation (ALDLT) to allow the recipients to meet their early metabolic demands. A persistent large spontaneous portosystemic shunt can divert portal flow away from the liver graft, leading to impaired or delayed graft regeneration and subsequent graft failure. The importance of obliterating huge portosystemic shunt during liver transplantation is obvious for successful ALDLT. However, in partial liver graft with a relatively small graft-to-recipient weight ratio (GRWR) (compared with deceased donor whole graft liver transplantation), even the persisting small portosystemic shunt may result in repeated portal flow steal when a liver graft faces increased intrahepatic vascular resistance caused by rejection or graft congestion with hepatic venous outflow stenosis. We present 2 complicated cases of reappearing portal flow steal that were derived from the remaining small portosystemic shunt under the increased vascular resistance of the liver graft, even after interruption of a large portosystemic shunt during ALDLT. Because ALDLT is always a partial liver graft, even when GRWR is over 1%, it is much more vulnerable to hemodynamic changes in portal flow by rejection or graft congestion by hepatic venous outflow obstruction. Therefore, a comprehensive understanding of complex portosystemic shunt and complete reinterruption of reappearing portosystemic shunt, even though small and insignificant, during ALDLT is important for graft salvage procedures before irreversible liver graft damage.

Endovascular transsplenic recanalization with angioplasty and stenting of an occluded main portal vein in an adult liver transplant recipient

Endovascular transshepatic access has limitations that can be exacerbated in the posttransplantation setting. Although several techniques are available for portal venous system catheterization, the transsplenic approach offers a direct pathway for accessing the portal venous system, as well as associated varices or shunts, while avoiding potential injury to the liver transplant. The purpose of this report is to present the diagnostic and interventional management of main portal vein occlusion in a 56-year-old female after liver transplantation. Endovascular transsplenic recanalization with stenting and shunt embolization is a viable method for treatment of main portal vein thrombosis in an adult liver transplant recipient.

Extensive Thrombectomy as a Legitimate Strategy in Living Donor Liver Transplantation With Advanced Portal Vein Thrombosis

Management of portal vein thrombosis (PVT), especially advanced PVT involving the superior mesenteric vein (SMV), in living donor liver transplantation (LDLT) is challenging. There were 514 adults who underwent LDLT between 2005 and 2018 included in this retrospective study, and PVT was observed in 67 (13.0%) patients. The LDLT recipients with PVT were characterized by increased portal pressure at laparotomy (26.1 ± 6.0 versus 24.3 ± 5.9 mm Hg; P = 0.03) and at closure (16.8 ± 3.9 versus 15.6 ± 3.6 mm Hg; P = 0.02), increased operative blood loss (14.6 ± 29.7 versus 5.7 ± 6.3 L; P < 0.01), and decreased 1-year graft survival (83.5% versus 92.8%; P = 0.04). Among the 18 patients with atrophic or vanished portal vein on pre-LDLT computed tomography, significant portal atrophy was actually observed only in 1 (5.6%) patient during LDLT surgery. For advanced PVT (n = 7) involving SMV in era 1, we performed nonanatomical inflow reconstruction using interposition grafts, resulting in significant inflow problems in 4 (57.1%) patients. Thus, for the patients with advanced PVT (n = 4) in era 2, we abandoned nonanatomical reconstruction and applied extensive thrombectomy under ultrasound guidance with secure shunt ligation, resulting in no inflow problems and no graft loss. In conclusion, even for advanced PVT involving SMV, extensive thrombectomy under sonogram guidance followed by anatomical inflow reconstruction and shunt ligation is a legitimate strategy in adult LDLT with PVT.

Portal flow modulation in living donor liver transplantation: review with a focus on splenectomy

Small-for-size graft (SFSG) syndrome after living donor liver transplantation (LDLT) is the dysfunction of a small graft, characterized by coagulopathy, cholestasis, ascites, and encephalopathy. It is a serious complication of LDLT and usually triggered by excessive portal flow transmitted to the allograft in the postperfusion setting, resulting in sinusoidal congestion and hemorrhage. Portal overflow injures the liver directly through nutrient excess, endothelial activation, and sinusoidal shear stress, and indirectly through arterial vasoconstriction. These conditions may be attenuated with portal flow modulation. Attempts have been made to control excessive portal flow to the SFSG, including simultaneous splenectomy, splenic artery ligation, hemi-portocaval shunt, and pharmacological manipulation, with positive outcomes. Currently, a donor liver is considered a SFSG when the graft-to-recipient weight ratio is less than 0.8 or the ratio of the graft volume to the standard liver volume is less than 40%. A strategy for transplanting SFSG safely into recipients and avoiding extensive surgery in the living donor could effectively address the donor shortage. We review the literature and assess our current knowledge of and strategies for portal flow modulation in LDLT.

Predictive Value of Hepatic Venous Pressure Gradient for Graft Hemodynamics in Living Donor Liver Transplantation

The hepatic venous pressure gradient (HVPG) measurement is known to correlate with the severity of portal hypertension in patients with liver cirrhosis. This retrospective study investigated the clinical value of preoperative measurement of HVPG in patients who underwent adult-to-adult living donor liver transplantation (LDLT) and its predictive value for hepatic hemodynamics after graft reperfusion. For this study, 75 patients who underwent adult-to-adult LDLT were divided into 2 groups (HVPG <16 mm Hg or HVPG ≥16 mm Hg) to investigate the correlation between preoperative HVPG and characteristics and surgical outcomes of the patients, including portal vein flow (PVF) and hepatic artery flow (HAF) after graft reperfusion. In total, 35 (46.7%) patients had an HVPG ≥16 mm Hg. These patients had significantly higher international normalized ratio values, serum creatinine levels, and Model for End-Stage Liver Disease scores compared with the 40 patients with HVPG <16 mm Hg. They also had higher rates of variceal bleeding, encephalopathy, and intractable ascites as well as lower serum albumin levels and platelet counts compared with those patients with HVPG <16 mm Hg. Portal inflow modulation (PIM) was frequently performed in the patients with HVPG ≥16 mm Hg compared with those with HVPG <16 mm Hg. No significant differences in surgical outcomes after LDLT were found between these 2 groups except for postoperative ascites. Preoperative HVPG showed a positive correlation with PVF and a negative correlation with HAF after graft reperfusion (false discovery rate [FDR] P = 0.08 and FDR P = 0.08, respectively). In linear regression analyses, preoperative HVPG was independently associated with PVF after graft reperfusion. In conclusion, our findings indicate that preoperative HVPG is associated with hepatic hemodynamics after graft implantation in LDLT. HVPG as a routine preoperative evaluation may be helpful for surgical planning of PIM.

Adult-to-adult living-donor liver transplantation: The experience of the Université catholique de Louvain

BACKGROUND

Liver transplantation is the treatment for end-stage liver diseases and well-selected malignancies. The allograft shortage may be alleviated with living donation. The initial UCLouvain experience of adult living-donor liver transplantation (LDLT) is presented.

METHODS

A retrospective analysis of 64 adult-to-adult LDLTs performed at our institution between 1998 and 2016 was conducted. The median age of 29 (45.3%) females and 35 (54.7%) males was 50.2 years (interquartile range, IQR 32.9-57.5). Twenty-two (34.4%) recipients had no portal hypertension. Three (4.7%) patients had a benign and 33 (51.6%) a malignant tumor [19 (29.7%) hepatocellular cancer, 11 (17.2%) secondary cancer and one (1.6%) each hemangioendothelioma, hepatoblastoma and embryonal liver sarcoma]. Median donor and recipient follow-ups were 93 months (IQR 41-159) and 39 months (22-91), respectively.

RESULTS

Right and left hemi-livers were implanted in 39 (60.9%) and 25 (39.1%) cases, respectively. Median weights of right- and left-liver were 810 g (IQR 730-940) and 454 g (IQR 394-534), respectively. Graft-to-recipient weight ratios (GRWRs) were 1.17% (right, IQR 0.98%-1.4%) and 0.77% (left, 0.59%-0.95%). One- and five-year patient survivals were 85% and 71% (right) vs. 84% and 58% (left), respectively. One- and five-year graft survivals were 74% and 61% (right) vs. 76% and 53% (left), respectively. The patient and graft survival of right and left grafts and of very small (<0.6%), small (0.6%-0.79%) and large (≥0.8%) GRWR were similar. Survival of very small grafts was 86% and 86% at 3- and 12-month. No donor died while five (7.8%) developed a Clavien-Dindo complication IIIa, IIIb or IV. Recipient morbidity consisted mainly of biliary and vascular complications; three (4.7%) recipients developed a small-for-size syndrome according to the Kyushu criteria.

CONCLUSIONS

Adult-to-adult LDLT is a demanding procedure that widens therapeutic possibilities of many hepatobiliary diseases. The donor procedure can be done safely with low morbidity. The recipient operation carries a major morbidity indicating an important learning curve. Shifting the risk from the donor to the recipient, by moving from the larger right-liver to the smaller left-liver grafts, should be further explored as this policy makes donor hepatectomy safer and may stimulate the development of transplant oncology.

Ligation versus no ligation of spontaneous portosystemic shunts during liver transplantation: Audit of a prospective series of 66 consecutive patients

The management of large spontaneous portosystemic shunt (SPSS) during liver transplantation (LT) is a matter of debate. The aim of this study is to compare the short-term and longterm outcomes of SPSS ligation versus nonligation during LT, when both options are available. From 2011 to 2017, 66 patients with SPSS underwent LT: 56 without and 10 with portal vein thrombosis (PVT), all of whom underwent successful thrombectomy and could have portoportal reconstruction. The SPSS were either splenorenal (n = 40; 60.6%), left gastric (n = 16; 24.2%), or mesenterico-iliac (n = 10; 15.1%). Following portoportal anastomosis, the SPSS was ligated in 36 (54.4%) patients and left in place in 30 (45.5%) patients, based on the effect of the SPSS clamping/unclamping test on portal vein flow during the anhepatic phase. Intraoperatively, satisfactory portal flow was obtained in both groups. Primary nonfunction (PNF) and primary dysfunction (PDF) rates did not differ significantly between the 2 groups. Nonligation of SPSS was significantly associated with a higher rate of postoperative encephalopathy (P < 0.001) and major postoperative morbidity (P = 0.02). PVT occurred in 0 and 3 patients in the ligated and nonligated shunt group, respectively (P = 0.08). A composite end point, which included the relevant complications in the setting of SPSS in LT (ie, PNF and PDF, PVT, and encephalopathy) was present in 16 (44.4%) and 22 (73.3%) patients of the ligated and nonligated shunt group, respectively (P = 0.02). Patient (P = 0.05) and graft (P = 0.02) survival rates were better in the ligated shunt group. In conclusion, the present study supports routine ligation of large SPSS during LT whenever feasible. Liver Transplantation 24 505-515 2018 AASLD.

Unusual spontaneous porto-systemic shunt: The importance of diagnosing non-anatomical porto-systemic shunts to improve portal flow in pediatric living-related liver transplantation. Case report

Collateral circulation secondary to liver cirrhosis may cause the development of large PSSs that may steal flow from the main portal circulation. It is important to identify these shunts prior to, or during the transplant surgery because they might cause an insufficient portal flow to the implanted graft. There are few reports of "steal flow syndrome" cases in pediatrics, even in biliary atresia patients that may have portal hypoplasia as an associated malformation. We present a 12-month-old female who received an uneventful LDLT from her mother, and the GRWR was 4.8. During the early post-operative period, she became hemodynamically unstable, developed ascites, and altered LFT. The post-operative ultrasound identified reversed portal flow, finding a non-anatomical PSS. A 3D CT scan confirmed the presence of a mesocaval shunt through the territory of the right gonadal vein, draining into the right iliac vein, with no portal inflow into the liver. The patient was re-operated, and the shunt was ligated. An intraoperative Doppler ultrasound showed adequate portal inflow after the procedure; the patient evolved satisfactorily and was discharged home on day number 49. The aim was to report a case of post-operative steal syndrome in a pediatric recipient due to a mesocaval shunt not diagnosed during the pretransplant evaluation.

Tips and pitfalls in direct ligation of large spontaneous splenorenal shunt during liver transplantation

Patients with large spontaneous splenorenal shunts (SRSs) prove challenging during liver transplantation (LT), regardless of organizing portal vein (PV) thrombosis. Here, we detail the clinical outcomes of 26 patients who underwent direct ligation of large SRSs during LT. Direct ligation of large SRS was applied in poor portal flow during LT. We performed temporary test clamping of the SRS before direct ligation and applied PV pressure monitoring in patients who showed signs of portal hypertension, such as bowel edema. We retrospectively reviewed and evaluated their clinical outcomes. Among 843 patients who underwent LT between 2010 and 2015, 26 (3.1%) underwent direct ligation of SRS without any intraoperative event. Mean preoperative Model for End-Stage Liver Disease score was 16.7 ± 9.0. The main PV diameter on preoperative computed tomography was 8.3 ± 3.4 mm (range, 3.0-14.0 mm). SRS was easily identified at just below the distal pancreas and beside the inferior mesenteric vein in all patients. Accompanying PV thrombectomy was done in 42.3% of patients. Among 26 patients, massive and prolonged ascites was evident in 15.4% (n = 4) postoperatively. They were all living donor LT recipients with a small PV diameter (4.0-6.7 mm). Except for 1 patient who underwent splenic artery embolization, ascites was tolerable and well controlled by conservative management. There was a 7.7% rate of major complications related to direct ligation, including reoperation due to combined ligation of SRS along with a left renal vein at the confluence. Except for 1 hospital mortality due to sepsis, 25 patients (96.2%) are alive with no evidence of further PV complications. In conclusion, direct ligation of large SRS during LT is a safe and feasible method to overcome the effects of a large SRS. Liver Transplantation 23 899-906 2017 AASLD.

Development of extensive inferior vena cava thrombosis due to the ligation of a large mesenteric-caval shunt during liver transplantation: A case report

•

We report a case of IVC thrombosis caused by ligation of large mesenteric-caval shunt.

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This case serves as a note of caution when addressing a major portosystemic shunts in LT.

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The position of large collateral ligation should be carefully considered in LT.

Instruction

Inferior vena cava (IVC) thrombosis can be a life-threatening complication after liver transplantation (LT). Although this complication is usually related to technical problems associated with vascular anastomosis, we report a case of IVC thrombosis which developed from a ligated large mesenteric-caval shunt.

Presentation of case

A 35-year-old man underwent LT from a brain-dead donor for primary sclerosing cholangitis. Enhanced computed tomography (CT) before LT showed a huge collateral vessel of the inferior mesenteric vein (IMV) draining into the infra-renal IVC directly. To obtain sufficient portal vein (PV) flow, the dilated IMV collateral was ligated. A routine Doppler ultrasound study on post-operative day 1 showed thrombus inside the infra-hepatic IVC. Enhanced CT showed that this thrombus originated from a ligated collateral vessel of the IMV and extended into the IVC. He was hemodynamically stable and liver function was consistently stable. The size of IVC thrombus slowly reduced and he is currently in good condition without any symptoms.

Discussion

To obtain adequate PV flow, ligation of a major PSS at the time of LT has been suggested. However, where it should be occluded has not been discussed. We should occlude a mesenteric-caval shunt not only at the upper side, but at the IVC side, based on findings from the current case.

Conclusion

To obtain appropriate PV flow toward a liver graft, occlusion of portosystemic shunts during LT is recommended. However, the position of ligation should be carefully considered to avoid extension of thrombus to major vessels.

Radiologic evaluation of portal steal phenomenon in recipients of liver transplantation

It is important to maintain adequate portal flow and to prevent the detrimental effect of portosystemic shunt in recipients following liver transplantation. The purpose of this article is to present a comprehensive review of portosystemic shunts and to illustrate such phenomenon demonstrated on radiologic studies such as Doppler ultrasound, computed tomography, and portogram. It is important for radiologists to be aware of such phenomenon not only in preoperative evaluation of the recipients but also in postoperative screening to detect recurrence of the phenomenon.

Graft selection strategy in adult-to-adult living donor liver transplantation: When both hemiliver grafts meet volumetric criteria

To ensure donor safety in living donor liver transplantation (LDLT), the left and caudate lobe (LL) is the preferred graft choice. However, patient prognosis may still be poor even if graft volume (GV) selection criteria are met. Our aim was to evaluate the effects of right lobe (RL) donation when the LL graft selection criteria are met. Consecutive donors (n = 135) with preoperative LL graft volumetric GV/standard liver volume (SLV) of ≥35% and RL remnant of ≥35% were retrospectively studied. Patients were divided into 2 groups: LL graft and RL graft. Recipient's body surface area (BSA), Model for End-Stage Liver Disease (MELD) score, and the donor's age were higher in the RL group. The donor's BSA and preoperative volumetric GV/SLV of the LL graft were smaller in the RL group. The predicted score (calculated using data for graft size, donor age, MELD score, and the presence of portosystemic shunt, which correlated well with graft function and with 6-month graft survival) of the RL group, was significantly lower if the LL graft were used, but using the actual RL graft improved the score equal to that of the LL group. Six-month and 12-month graft survival rates did not differ between the 2 groups. In patients with a poor prognosis, a larger RL graft improved the predicted score and survival was equal to that of patients who received LL grafts. In conclusion, graft selection by GV, donor age, and recipient MELD score improves outcomes in LDLT. Liver Transplantation 22 914-922 2016 AASLD.

Outcomes of adult-to-adult living donor liver transplantation in 321 recipients

We conducted a retrospective investigation in order to clarify whether selecting the type of liver graft had an impact on outcomes of adult-to-adult living donor liver transplantation (AALDLT). Data from the medical records of the donors and the recipients of 321 consecutive cases of AALDLT performed between April 2004 and March 2014 were retrospectively analyzed. Our general criteria for selecting the type of liver graft was that a left graft was preferentially selected when the estimated volume of the left graft was ≥35% of the standard liver volume of the recipient, and that a right graft was selected only when the estimated remnant liver volume of the donor was ≥35% of the total liver volume. In this series, 177 left grafts, 136 right grafts, and 8 posterior grafts were used. The left grafts tended to have 2 or more arteries, whereas the right grafts tended to have 2 or more bile duct orifices. The graft survival curves and the incidences of severe complications were comparable between the AALDLT using right grafts and the AALDLT using left grafts. The preoperative estimation of graft size hardly enabled us to predict severe posttransplant complication. Moreover, small-for-size graft syndrome occurred regardless of the estimated graft volumes. Instead, donor age was a significant risk factor for small-for-size graft syndrome. In conclusion, left grafts should be more aggressively used for the sake of donors' safety. The use of hepatic grafts from older donors should be avoided if possible in order to circumvent troublesome posttransplant complications.

Portal flow steal after liver transplantation

Portal flow steal occasionally persists even after the liver transplantation, which may reduce the portal flow and thus threaten the patients' outcome. Therefore, pre- and peri-operative detection of portal steal phenomenon requiring radiological or surgical interruption is essential for the liver transplantation candidates as well as for the recipients.

Portal vein reconstruction in adult living donor liver transplantation for patients with portal vein thrombosis in single center experience

BACKGROUND

Liver transplantation (LT) used to be contraindicated in patients with portal vein thrombosis (PVT). In comparison to deceased donor LT, living donor LT (LDLT) still presents additional difficulties in determining appropriate vein grafts and overcoming small-for-size syndrome. Here, we introduce our LDLT strategies and assess their outcomes in adult patients with pre-existing PVT.

METHODS

We performed 282 consecutive adult LDLTs between April 2006 and December 2011. Forty-eight patients (17%) had pre-existing PVT (grade I; 15, II; 20, III; 12, IV; 1).

RESULTS

Our preferred treatments for PVT were thrombectomies/thromboendovenectomies in 30 patients, replaced grafts in seven, jump grafts in seven, renoportal anastomosis in one and no surgical intervention owing to minimal thrombosis in three. Post-transplant portal vein complications occurred in eight of 48 (17%) cases, which were treated by surgery, anticoagulation therapy, and/or interventional radiology. Post-transplant survival rates of patients with preexisting PVT at 1 year and 5 years were comparable to a PVT-free cohort (1 year; 81% vs. 77%, 5 years; 81% vs. 73%).

CONCLUSIONS

The excellent survival rates in patients with PVT who underwent LDLT could be attributed to our strategies, which included surgical techniques and timely treatment of postoperative complications.

Clinical significance of gastrointestinal bleeding after living donor liver transplantation

The clinical presentations of gastrointestinal bleeding (GIB) occurring after living donor liver transplantation (LDLT) have not been fully described. We performed a retrospective analysis of 297 LDLT cases. Nineteen patients (6.4%) experienced GIB after LDLT. The etiology of GIB included bleeding at the jejunojejunostomy following hepaticojejunostomy (n = 13), peptic ulcer disease (n = 2), portal hypertensive gastropathy (n = 2), and other causes (n = 2). Hemostasis was achieved in 13 patients (68.4%) by endoscopic (n = 3), surgical (n = 1), or supportive treatments (n = 15), but not in the other six patients. Graft dysfunction (P < 0.001), hepaticojejunostomy (P = 0.01), portal vein pressure at the end of surgery >20 mmHg (P = 0.002), and operative blood loss >10 L (P = 0.004) were risk factors. One-year graft survival rate was significantly lower in patients with GIB than in patients without GIB (P < 0.001). The inhospital mortality rate was 52.6% for patients with GIB, 75.0% for patients with graft dysfunction, and 14.3% for patients without graft dysfunction (P = 0.028). Despite its infrequency after LDLT, GIB has strong correlation with graft dysfunction and inhospital mortality.

Re-evaluation of the predictive score for 6-month graft survival in living donor liver transplantation in the modern era

The limitations of donor age, graft size, and the Model for End-Stage Liver Disease (MELD) score have not been apparent in living donor liver transplantation (LDLT). Our team developed a formula for predicting graft survival after LDLT; the formula includes the graft weight, donor age, MELD score, and portosystemic shunt status. The aims of this study were to re-evaluate the reliability of our formula and to assess whether our modified treatment strategy has improved 6-month graft survival. Two hundred seventeen patients were allocated into 2 groups: patients with predictive scores ≥ 1.30 (n = 162) and patients with predictive scores < 1.30 (n = 55). The latter group was also divided into subgroups of patients with scores of 1.15 to 1.30 (n = 37) and patients with scores < 1.15 (n = 18). Survival rates for patients with scores < 1.30 were significantly worse than rates for patients with scores ≥ 1.30 (P = 0.006). Survival rates for patients with scores < 1.15 were significantly worse than rates for patients with scores of 1.15 to <1.30 (P < 0.001). A multivariate analysis showed that a predictive score < 1.15 (odds ratio = 7.87, P = 0.006) and a body mass index ≥ 30 kg/m(2) (odds ratio = 13.3, P < 0.001) were independent risk factors for 6-month graft mortality. In conclusion, predictive scores reliably predict 6-month graft survival and could allow a widening of the safe ranges for donor ages and graft sizes.