Emergency Liver Retransplantation With Marginal Donors

BACKGROUND

The goal of the present study is to determine if using marginal donors negatively impacts the outcomes of emergency liver retransplantation.

METHODS

A retrospective case-control study was performed, including all emergency liver retransplantations done in our center between 1990 and 2021. Recipients from the control group received the second grafts from "ideal donors", and patients from the case group received them from marginal donors. Analyzed variables included demographics of recipients and donors, complications, and survival rates.

RESULTS

38 emergency retransplantations were performed. 23 recipients were included in the control group, and the remaining 15 were in the case group. The second donors from the case group were significantly older (mean age 58 vs 71 years old, P < 0.0001). On the contrary, there were no differences between groups regarding the mean age of recipients, comorbidities, Model for End-Stage Liver Disease scores, or causes of retransplantation (the most common was hepatic artery thrombosis). No differences were found in early perioperative death rates (control group 26.1% vs case group 20%, P =1) and, although the case group seemed to have slightly poorer outcomes in long-term survival (control group 70%, 61%, and 55% vs case group 73%, 59%, and 39%, respectively, at 1, 5, and 10 years), the differences were not statistically significant (log-rank = 0.808).

CONCLUSIONS

The use of marginal donors for emergency liver retransplantation was proved safe in our study, as there were no differences in complications or in short- or mid-term survival rates.

Development of a liver graft assessment expert machine-learning system: when the artificial intelligence helps liver transplant surgeons

Background

The complex process of liver graft assessment is one point for improvement in liver transplantation. The main objective of this study is to develop a tool that supports the surgeon who is responsible for liver donation in the decision-making process whether to accept a graft or not using the initial variables available to it.

Material and method

Liver graft samples candidate for liver transplantation after donor brain death were studied. All of them were evaluated "in situ" for transplantation, and those discarded after the "in situ" evaluation were considered as no transplantable liver grafts, while those grafts transplanted after "in situ" evaluation were considered as transplantable liver grafts. First, a single-center, retrospective and cohort study identifying the risk factors associated with the no transplantable group was performed. Then, a prediction model decision support system based on machine learning, and using a tree ensemble boosting classifier that is capable of helping to decide whether to accept or decline a donor liver graft, was developed.

Results

A total of 350 liver grafts that were evaluated for liver transplantation were studied. Steatosis was the most frequent reason for classifying grafts as no transplantable, and the main risk factors identified in the univariant study were age, dyslipidemia, personal medical history, personal surgical history, bilirubinemia, and the result of previous liver ultrasound (p < 0.05). When studying the developed model, we observe that the best performance reordering in terms of accuracy corresponds to 76.29% with an area under the curve of 0.79. Furthermore, the model provides a classification together with a confidence index of reliability, for most cases in our data, with the probability of success in the prediction being above 0.85.

Conclusion

The tool presented in this study obtains a high accuracy in predicting whether a liver graft will be transplanted or deemed non-transplantable based on the initial variables assigned to it. The inherent capacity for improvement in the system causes the rate of correct predictions to increase as new data are entered. Therefore, we believe it is a tool that can help optimize the graft pool for liver transplantation.

A scoring system for predicting malignancy in intraductal papillary mucinous neoplasms of the pancreas: a multicenter EUROPEAN validation

PURPOSE

A preoperative estimate of the risk of malignancy for intraductal papillary mucinous neoplasms (IPMN) is important. The present study carries out an external validation of the Shin score in a European multicenter cohort.

METHODS

An observational multicenter European study from 2010 to 2015. All consecutive patients undergoing surgery for IPMN at 35 hospitals with histological-confirmed IPMN were included.

RESULTS

A total of 567 patients were included. The score was significantly associated with the presence of malignancy (p < 0.001). In all, 64% of the patients with benign IPMN had a Shin score < 3 and 57% of those with a diagnosis of malignancy had a score ≥ 3. The relative risk (RR) with a Shin score of 3 was 1.37 (95% CI: 1.07-1.77), with a sensitivity of 57.1% and specificity of 64.4%.

CONCLUSION

Patients with a Shin score ≤ 1 should undergo surveillance, while patients with a score ≥ 4 should undergo surgery. Treatment of patients with Shin scores of 2 or 3 should be individualized because these scores cannot accurately predict malignancy of IPMNs. This score should not be the only criterion and should be applied in accordance with agreed clinical guidelines.

Risk Factors for No Valid Liver Graft. Multivariate Study Based on the Variables Included in the Donation Protocol of the National Trasplant Organisation

INTRODUCTION

Among the strategies designed to optimize the number of existing liver grafts for transplantation, the implementation of the graft assessment process is one of the least explored. The main objective is to identify the risk factors presented by liver donors for «NO validity». Secondly, we analyzed the coincidence between the surgeon's assessment and that of the anatomo-pathologist in the invalid donors.

MATERIAL AND METHOD

Retrospective study conducted from a prospective database that analyzes 190 liver donors, 95 valid and 95 NOT valid. The variables of each of them corresponding to the donation protocol of the National Transplant Organization are studied. Through a multivariate study we determine the independent risk factors of NO validity. We checked the causes of NO validity argued with the histopathological findings of these grafts.

RESULTS

The independent risk factors of non-validity in the multivariate study (P < .05) were: dyslipidemia, personal medical history other than cardiovascular and abdominal surgical risk factors, GGT, BrT, and the result of previous liver ultrasound. The 3 most frequent causes of NO validity were: steatosis, fibrosis and macroscopic appearance of the organ. 78% of the biopsies confirmed the NO validity of the graft (in 57.9% of the cases the histological findings coincided with those described by the surgeon). The 22.1% of the biopsies hadńt pathological findings.

CONCLUSIONS

The determination of the risk factors of NO validity will contribute to the design of future assessment scores that are useful tools in the process of liver graft assessment.).

Results of Early Liver Retransplantation

BACKGROUND

Liver retransplantation can be classified as urgent (when performed in the first week after the transplantation) or elective, which may be considered as early (first month post-transplantation) or late (after the first month). The time in which retransplantation takes place is determined by the cause that makes it necessary. The goal of this study is to analyze the causes and results of early retransplantation in our center.

METHODS

A retrospective analysis of liver retransplantations performed within the first month after the original transplantation in our center between 2007 and 2017 was carried out. The variables analyzed were demographic, causes of the first transplant and retransplantation, and the complications and mortality resulting from the latter.

RESULTS

A total of 698 liver transplants were performed, including 67 patients who required retransplantation (8.9%). Among these, 37 were late elective retransplantations and 30 were early retransplantations. Regarding the latter, the causes that led to the first transplant were hepatocellular carcinoma (46.7%) and noncholestatic cirrhosis (30%). On the other hand, the main precipitants of the retransplantation were hepatic artery thrombosis (60%) and primary graft failure (13.3%). The reoperation rate was 16.7%, and the perioperative mortality rate was 16.7%. The 1-, 2-, and 5-year survival rates were 83.3%, 76.7% and 59.9%, respectively.

CONCLUSION

Despite the high perioperative morbidity of liver retransplantation, its results in terms of survival are similar to those of the global series of liver transplantation.

Management of Large, Spontaneous Portosystemic Shunts in Liver Transplantation: Case Report and Review of Literature

BACKGROUND

The presence of collateral circulation in liver cirrhosis patients with portal hypertension is quite frequent due to re-permeabilization of closed embryonic channels. In some cases, these shunts could measure over 1 cm wide, therefore, containing a significative blood flow. Its management during liver transplantation could be challenging due to possible complications resulting from either ligation of the shunts or from ignoring them. We present the case of a patient with recurrent hepatic encephalopathy (HE) and a large spontaneous portosystemic shunt (SPSS) who submitted to liver transplant and review the literature identifying options, complications, and outcomes with the aim of facilitating decision making.

MATERIAL AND METHODS

A 68-year-old, Spanish man diagnosed with liver cirrhosis with portal hypertension and recurrent episodes of HE is proposed for LT. The patient's Child-Pugh score was A6-B7, and the Model for End-stage Liver Disease score was 12. Preoperatively, a computed tomography scan showed a large SPSS running to the inferior cava vein. During the surgery, a small-sized portal vein and a large shunt measuring almost 3 cm wide were identified. After reperfusion, portal vein flow was 1000 to 1100 mL/min. Owing to the previous HE and the risk of low portal flow, the shunt was closed increasing the portal flow to 1800 mL/min. The patient was discharged without any complications.

CONCLUSIONS

The presence of large SPSSs are frequent during LT. Decision making intraoperatively can be challenging due to possible complications derived from ligation of the SPSS or from ignoring it. Either preoperative assessment of a further HE risk or portal vein flow measurement after reperfusion are essential to achieve a correct resolution.

Pancreatobiliary maljunction: association with gallbladder cancer

BACKGROUND

Pancreatobiliary maljunction is a rare disease characterized by the junction of the pancreatic and biliary ducts outside of the duodenal wall, which normally results in a large common duct. As a result, there is a greater risk of acute pancreatitis and cancer of the gallbladder and biliary tract.

CASE REPORT

We present the case of a 43-year-old female diagnosed with a pancreatobiliary maljunction and an associated stenosis of the bile duct, secondary to an episode of acute pancreatitis. She underwent several endoscopic retrograde cholangiopancreatography procedures over the course of three years, without improvement of the stenosis, and therefore a surgical approach was taken. Prior to the surgical intervention, magnetic resonance imaging showed the presence of an 11-mm polyp in the gallbladder. A histological study of the surgical sample identified intramucosal adenocarcinoma over a tubular adenoma of the gallbladder.

DISCUSSION

Pancreatobiliary maljunction can be considered as a premalignant entity due to the risk of developing cancer of the biliary tree and gallbladder. Therefore, these patients should undergo a prophylactic intervention, despite being asymptomatic.

Intraoperative Portal Vein Flow > 123 mL/min Per 100 g Predicts a Better Survival of Patients After Liver Transplantation

OBJECTIVE

To assess the importance of intraoperative portal vein flow measurement during liver transplantation in relation to postoperative complications and graft and patient survival.

MATERIALS AND METHODS

Retrospective review including 291 patients who had all the information and covering a period of 10 years (2007-2017). Using a receiver operating characteristic curve, a cut-off point that would have the greatest impact on the probability of being alive at 5 years was established. In relation to this value, 2 groups were formed (low and high flow) and demographic variables, intraoperative variables, postoperative complications, and graft and patient survival were compared.

RESULTS

A portal flow of 123 mL/min per100 g of liver tissue was established (area under the curve = 0.58), obtaining a low-flow (n = 129) and a high-flow group (n = 162). The 2 groups were similar in their preoperative characteristics, except for a higher proportion of preoperative ascites, a higher Model for End-Stage Liver Disease score and a lower weight of donors in the high-flow group. The arterial and portal flows were significantly higher in the high-flow group. In the postoperative period, the high-flow group presented a higher rate of ascites. The 5-year survival rate of patients was significantly higher in the high-flow group (76% vs 84%, P = .03).

CONCLUSIONS

Patients undergoing liver transplantation with an intraoperative portal vein flow measurement >123 mL/min per 100 g present a greater 5-year survival rate.

Hepatocellular carcinoma in patients without advanced fibrosis after HCV eradication antiviral treatment

From the last few years, hepatitis C virus and the new direct antiviral treatments are being more and more important. In consequence, case studies like the one we present, the appearance of hepatocelullar carcinoma after its eradication with fibrosis grade 2, are getting special interest. In 2007, our patient was treated with pegylated interferon α-2a and ribavirin, having a sustained virological response after it. In this way, liver fibrosis grade 2 was confirmed by a biopsy. Finally, after corroborating a good liver functioning, the patient was discharged (as, according to the guidebooks, an ultrasound scan of screeing every 6 months was not required). In 2014, the patient came to hospital because of a pain at right hypochondrium and he was diagnosed with hepatocelullar carcinoma. A hepatectomy was done objectifying the surgical piece, liver fibrosis grade 2, one more time. Subsequently, a tumour relapse through an abdominal CT scan, a tumour relapse was found and despite the Sorafenib treatment, the patient died on January 2015. This case study provokes curiosity and uncertainty about the attitude which should be taken respect to the monitoring, and hepatocelullar carcinoma screening overall, in patients with a sustained virological response after eradicator treatment and without advanced fibrosis. Nowadays, with the benefits of the new treatments, the amount of patients in this situation is increasing significantly.

Post-transplant lymphoproliferative disease in liver transplant recipients

INTRODUCTION

Post-transplant lymphoproliferative syndrome (PTLD) is a rare and potentially life-threatening complication after liver transplantation. The aim of this study was to analyze the clinicopathologic features related to PTLD in a single institution after liver transplantation.

METHODS

Observational study where we have retrospectively analyzed 851 cases who underwent liver transplantation. Ten cases have developed PTLD. Their clinical-pathological characteristics and the treatment received have been analyzed.

RESULTS

PTLD incidence was 1.2% (10/851). The mean time from liver transplantation to PTLD diagnosis was 36 months (range 1.2 to 144 months). PTLD localization was extranodal in all cases, the most frequent location being intestinal. Seven cases showed a monomorphic lymphoma which in all cases was differentiated B cell lymphomas. Fifty per cent of the series were seropositive for Epstein-Barr virus. Five patients were alive at the time of the review. Among these patients, we observed three cases of complete remission and two cases of disease stabilization. The death rate was higher in the first year after diagnosis of PTLD.

CONCLUSION

PTLD is a rare complication after liver transplantation, but it may pose a threat to the life of a liver transplant recipient. It is essential to identify patients at risk, to establish an early diagnosis and treatment that can change the outcome of the disease.

Fibrinogen-thrombin collagen patch reinforcement of high-risk colonic anastomoses in rats

AIM

To evaluate the effectiveness of human fibrinogen-thrombin collagen patch (TachoSil^®) in the reinforcement of high-risk colon anastomoses.

METHODS

A quasi-experimental study was conducted in Wistar rats (n = 56) that all underwent high-risk anastomoses (anastomosis with only two sutures) after colectomies. The rats were divided into two randomized groups: Control group (24 rats) and treatment group (24 rats). In the treatment group, high-risk anastomosis was reinforced with TachoSil^® (a piece of TachoSil^® was applied over this high-risk anastomosis, covering the gap). Leak incidence, overall survival, intra-abdominal adhesions, and histologic healing of anastomoses were analyzed. Survivors were divided into two subgroups and euthanized at 15 and 30 d after intervention in order to analyze the adhesions and histologic changes.

RESULTS

Overall survival was 71.4% and 57.14% in the TachoSil^® group and control group, respectively (P = 0.29); four rats died from other causes and six rats in the treatment group and 10 in the control group experienced colonic leakage (P > 0.05). The intra-abdominal adhesion score was similar in both groups, with no differences between subgroups. We found non-significant differences in the healing process according to the histologic score used in both groups (P = 0.066).

CONCLUSION

In our study, the use of TachoSil^® was associated with a non-statistically significant reduction in the rate of leakage in high-risk anastomoses. TachoSil^® has been shown to be a safe product because it does not affect the histologic healing process or increase intra-abdominal adhesions.