Vascular Complications After Liver Transplantation

Perioperative Complications After Pediatric Liver Transplantation-A Retrospective Analysis of 421 Cases

BACKGROUND

Due to the low incidence of pediatric liver transplantations, short- and long-term data regarding their outcome, details on early postoperative complications and their risk factors are under-represented in the literature.

METHODS

We retrospectively reviewed 1645 LTx performed at Hannover Medical School between January 2005 and December 2021. Of these, 421 transplantations were performed in 405 pediatric recipients. Univariate and multivariate binary logistic regressions were performed to identify independent risk factors for the onset of selected perioperative complications requiring intervention within the first 30 days following transplantation and their influence on graft and patient survival.

RESULTS

Pleural effusions represent the most common postoperative complication observed in 49.4% (n = 208) of cases, followed by vascular complications in 22.6% (n = 95) and biliary complications in 20.0% (n = 84) of cases. Donor age (OR: 1.019; p = 0.010) and recipient age between 3 and 12 years (OR: 1.849; p = 0.008) were identified as independent risk factors for the onset of pleural effusions. Retransplantations within the first year after LTx were necessary in 11.4% of all cases (n = 48). Twenty (4.8%) patients died within the first year after LTx.

CONCLUSION

Pleural effusions requiring postoperative intervention were observed in approximately half of the pediatric recipients. Therefore, the preemptive intraoperative placement of a chest drain under sterile conditions and general anesthesia should be considered. Our data further indicate that a two-stage procedure for biliary reconstruction may be the preferred procedure in patients at risk of early bile duct complications and retransplantation within the first year.

European Society of Pediatric Radiology survey of perioperative imaging in pediatric liver transplantation: (2) intraoperative imaging

BACKGROUND

Liver transplantation is the state-of-the-art curative treatment for end-stage liver disease. Imaging is a key element in the detection of intraoperative and postoperative complications. So far, only limited data regarding the best radiological approach to monitor children during liver transplantation is available.

OBJECTIVE

To harmonize the imaging of pediatric liver transplantation, the European Society of Pediatric Radiology Abdominal Taskforce initiated a survey addressing the current status of imaging including the pre-, intra- and postoperative phase. This paper reports the responses related to intraoperative imaging.

MATERIALS AND METHODS

An online survey, initiated in 2021, asked European centers performing pediatric liver transplantation 48 questions about their imaging approach. In total, 26 centers were contacted, and 22 institutions from 11 countries returned the survey.

RESULTS

Intraoperative ultrasound (US) is used by all sites to assess the quality of the vascular anastomosis in order to ensure optimal perfusion of the liver transplant. Vessel depiction is commonly achieved using color Doppler (95.3%). Additional US-based techniques are employed by fewer centers (power angio mode, 28.6%; B-flow, 19%; contrast-enhanced US, 14.3%). Most centers prefer a collaborative approach, with surgeons responsible for probe handling, while radiologists operate the US machine (47.6%). Less commonly, the intraoperative US is performed by the surgeon alone (28.6%) or by the radiologist alone (23.8%). Timing of US, imaging frequency, and documentation practices vary among centers.

CONCLUSION

Intraoperative US is consistently utilized across all sites during pediatric liver transplantation. However, considerable variations were observed in terms of the US setup, technique preferences, timing of controls, and documentation practices. These differences provide valuable insights for future optimization and harmonization studies.

Perioperative prothrombin complex concentrate and fibrinogen administration are associated with thrombotic complications after liver transplant

BACKGROUND

Use of intraoperative prothrombin complex concentrates (PCC) and fibrinogen concentrate administration has been linked to thrombotic events. However, it is unknown if its use is associated with thrombotic events after liver transplant.

METHODS AND ANALYSIS

We conducted a post hoc analysis of a prospectively conducted registry database study on patients who underwent liver transplant between 2004 and 2017 at Heidelberg University Hospital, Heidelberg, Germany. Univariate and multivariate analyses were used to determine the association between PCC and fibrinogen concentrate administration and thrombotic complications.

RESULTS

Data from 939 transplantations were included in the analysis. Perioperative PCC or fibrinogen administration was independently associated with the primary composite endpoint Hepatic artery thrombosis (HAT), Portal vein thrombosis (PVT), and inferior vena cava thrombosis [adjusted HR: 2.018 (1.174; 3.468), p = 0.011]. PCC or fibrinogen administration was associated with the secondary endpoints 30-day mortality (OR 4.225, p < 0.001), graft failure (OR 3.093, p < 0.001), intraoperative blood loss, red blood cell concentrate, fresh frozen plasma and platelet transfusion, longer hospitalization, and longer length of stay in intensive care units (ICUs) (all p < 0.001). PCC or fibrinogen administration were not associated with pulmonary embolism, myocardial infarction, stroke, or deep vein thrombosis within 30 days after surgery.

CONCLUSION

A critical review of established strategies in coagulation management during liver transplantation is warranted. Perioperative caregivers should exercise caution when administering coagulation factor concentrate during liver transplant surgery. Prospective randomized controlled trials are needed to establish causality for the relationship between coagulation factors and thrombotic events in liver transplantation. Further studies should be tailored to identify patient subgroups that will likely benefit from PCC or fibrinogen administration.

Concurrent Change in Serum Cholinesterase Activity and Midregional-Proadrennomedullin Level Could Predict Patient Outcome following Liver Transplantation

Background: After liver transplantation (LTX), patients are susceptible to opportunistic infections resulting in reduced outcomes within the early post-transplantation period. The postoperative monitoring of LTX patients has gained much importance in recent years. However, reliable plasmatic markers predicting 90-day outcomes are still lacking. Methods: In the post hoc analysis of a prospective, observational study, butyrylcholinesterase (BChE), mid-regional proadrenomedullin (MR-proADM), as well as conventional inflammatory markers (procalcitonin, C-reactive protein) were evaluated in 93 patients at seven consecutive timepoints within the first 28 days following LTX. Results: Persistently reduced activity of BChE and elevated MR-proADM levels indicated reduced 90-day survival following LTX. Furthermore, reduced BChE and increased MR-proADM activity could indicate early post-transplantation bacterial infections, whereas conventional inflammatory biomarkers showed no diagnostic efficacy within the observation period. Conclusion: Concurrent assessment of BChE and MR-proADM activity might serve as a bedside diagnostic tool for early bacterial infections following liver transplantation. Thus, a combined utilization of the two biomarkers may be a useful tool in the risk evaluation of patients following liver transplantation.

Improving the Specificity of CT Angiography for the Diagnosis of Hepatic Artery Occlusion after Liver Transplantation in Suspected Patients with Doppler Ultrasound Abnormalities

OBJECTIVE

To investigate whether the diagnostic performance of CT angiography (CTA) could be improved by modifying the conventional criterion (anastomosis site abnormality) to diagnose hepatic artery occlusion (HAO) after liver transplantation (LT) in suspected patients with Doppler ultrasound (US) abnormalities.

MATERIALS AND METHODS

One hundred thirty-four adult LT recipients (88 males and 46 females; mean age, 52.7 years) with suspected HAO on Doppler US (40 HAO and 94 non-HAO according to the reference standards) were included. We evaluated 1) abnormalities in the HA anastomosis, categorized as a cutoff, ≥ 50% stenosis at the anastomotic site, or diffuse stenosis at both graft and recipient sides around the anastomosis, and 2) abnormalities in the distal run-off, including invisibility or irregular, faint, and discontinuous enhancement. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the conventional (considering anastomosis site abnormalities alone) and modified CTA criteria (abnormalities in both the anastomosis site and distal run-off) for the diagnosis of HAO were calculated and compared using the McNemar test.

RESULTS

By using the conventional criterion to diagnose HAO, the sensitivity, specificity, PPV, NPV, and accuracy were 100% (40/40), 74.5% (70/94), 62.5% (40/64), 100% (70/70), and 82.1% (110/134), respectively. The modified criterion for diagnosing HAO showed significantly increased specificity (93.6%, 88/94) and accuracy (93.3%, 125/134) compared to that with the conventional criterion (p = 0.001 and 0.002, respectively), although the sensitivity (92.5%, 37/40) decreased slightly without statistical significance (p = 0.250).

CONCLUSION

The modified criterion considering abnormalities in both the anastomosis site and distal run-off improved the diagnostic performance of CTA for HAO in suspected patients with Doppler US abnormalities, particularly by increasing the specificity.

The "W" Technique: A Safe and Reproducible Technique for Hepatic Artery Reconstruction in Living Donor Liver Transplantation

BACKGROUND Reconstruction of the hepatic arterial inflow can be technically demanding in living donor liver transplantation, and thrombosis can result in graft loss and mortality. We describe the safe and reproducible "W" technique to reconstruct the hepatic artery and outcomes before and after adoption of the technique in a consecutive series of liver transplants at 2 high-volume living donor liver transplant centers. MATERIAL AND METHODS Prospectively collected data were analyzed to compare the outcomes before and after introduction of a standardized "W" technique for reconstruction of the hepatic artery in 2 high-volume living donor liver transplant programs. RESULTS In a consecutive series of 675 liver transplants, of which 27 were deceased donor transplants and 648 were living donor transplants, 443 transplants were performed with a standard interrupted reconstruction of the hepatic artery under loupes. These transplants were performed by a single surgeon, with an incidence of hepatic artery thrombosis of 2%. After introduction of the "W" technique, despite the arterial reconstruction being done by several surgeons in the early part of their learning curve, the incidence of hepatic artery thrombosis decreased to 0.86% in the next 232 transplants. CONCLUSIONS The "W" technique is a simple, easy to learn and teach technique for reconstruction of the hepatic artery without the use of the operating microscope in living donor liver transplantation.

The Utilization and Diagnostic Yield of Upper Endoscopy for Evaluation of Gastrointestinal Symptoms Within the First Year After Liver Transplantation

Background Gastrointestinal (GI) symptoms impact quality of life and increase health care utilization after liver transplantation (LTx). Esophagogastroduodenoscopy (EGD) is commonly used to investigate these symptoms. Aims The aim of this study was to investigate the diagnostic yield and utilization of EGD after LTx for common GI symptoms. Methods This single-center retrospective cohort study was conducted at a large liver transplant center and included all adults who underwent EGD within the first year after receiving LTx between January 1, 2015, and December 31, 2016. Biliary procedures were excluded. Results Of 437 patients who underwent LTx during the study period, 64 (15%) underwent EGD for the evaluation of GI symptoms within the first year of transplantation. After applying exclusion criteria, 57 (13%) cases were analyzed. GI hemorrhage (hematemesis/melena) was the most common reason (4%; n=18) for evaluation with EGD followed by nausea/anorexia (3%; n=12). Symptoms were investigated with EGD, including epigastric/abdominal pain (2%; n=9), dysphagia/odynophagia (2%; n=8), anemia (1%; n=5), diarrhea (1%; n=4), and heartburn (0.2%; n=1). The diagnostic yield of EGD was highest with GI hemorrhage (83%) followed by dysphagia/odynophagia (75%). EGD diagnostic yield was lower for the other symptoms, ranging from 0% to 25%. Conclusions EGD was commonly utilized within the first year of LTx, with the highest diagnostic yields for GI hemorrhage and dysphagia/odynophagia. Because of the low diagnostic yield of EGD for other symptoms, we recommend a careful selection of patients for EGD following LTx.

Impact of Microsurgical Anastomosis of Hepatic Artery on Arterial Complications and Survival Outcomes After Liver Transplantation

Hepatic artery (HA) complications after liver transplant (LT) can lead to biliary complications, graft failure, and mortality. Although microsurgery has been established to improve anastomotic outcomes, it prolongs surgical time and has not reached widespread adoption at all transplant centers. We investigated the incidences of arterial, biliary complications and outcomes after using microsurgery to anastomose HA during LT. Retrospective cohort of consecutive LT performed from 2006 to 2018 was reviewed for operative details and postoperative outcomes. Cox-regression models were used to investigate the relationship between variables and outcomes. Eighty (62.5%) LTs (Group 1) were performed without and compared with 48 (Group 2) with microsurgical anastomosis of HA. Both groups were comparable in terms of arterial and biliary anastomoses performed. Incidence of early HA thrombosis was similar (6.2% vs 2.1%, P = .28). Group 2 had lower incidence of short- and long-term arterial complications, especially amongst living donor liver transplantations (LDLT) (5.3% vs 35.0%, P = .022). On multivariate analysis, microsurgery was associated with lower risk (hazard ratio [HR] 0.09, 95% confidence interval [CI] 0.01-0.71) of, and LDLT had higher risk (HR 4.23, 95% CI 1.46-12.27) of arterial complications. Biliary complications were associated with LDLT (HR 3.91, 95% CI 1.30-11.71) and dual biliary anastomoses (HR 5.26, 95% CI 1.15-24.08) but not with occurrence of HA complications. Worse patient survival was associated with the occurrence of any HA complication (HR 4.11, 95% CI 1.78-9.48). Hepatic arterial complications can be reduced using microsurgical techniques for the anastomosis, resulting in improved patient survival outcomes after liver transplantation.

Influence of postoperative complications on long-term survival in liver transplant patients

BACKGROUND

Liver transplant (LT) is a complex procedure with frequent postoperative complications. In other surgical procedures such as gastrectomy, esophagectomy or resection of liver metastases, these complications are associated with poorer long-term survival. It is possible this happens in LT but there are not enough data to establish this relationship.

AIM

To analyze the possible influence of postoperative complications on long-term survival and the ability of the comprehensive complication index (CCI) to predict this.

METHODS

Retrospective study in a tertiary-level university hospital. The 164 participants were all patients who received a LT from January 2012 to July 2019. The follow-up was done in the hospital until the end of the study or death. Comorbidity and risk after transplantation were calculated using the Charlson and balance of risk (BAR) scores, respectively. Postoperative complications were graded according to the Clavien-Dindo classification and the CCI. To assess the CCI cut-off value with greater prognostic accuracy a receiver operating characteristic (ROC) curve was built, with calculation of the area under the curve (AUC). Overall survival was estimated according to the Kaplan-Meier test and log-rank test. Groups were compared by the Mann-Whitney test. For the multivariable analysis the Cox regression was used.

RESULTS

The mean follow-up time of the cohort was 37.76 (SD = 24.5) mo. A ROC curve of CCI with 5-year survival was built. The AUC was 0.826 (0.730-0.922), P < 0.001. The cut-off was calculated by means of the Youden index with a result of 35.95. The sensitivity was 84.6% and the specificity 61.3%. Survival curves for comparison of patients with CCI score < 36 vs ≥ 36 were calculated. The estimated 5-year survival was 57.65 and 43.95 months, respectively (log-rank < 0.001). This suggests that patients with more severe complications exhibit worse long-term survival. Other cut-off values were analysed. Comparison between patients with CCI < 33.5 vs > 33.5 (33.5 = median CCI value) showed estimated 5-year survival was 57.4 and 45.71 months, respectively (log-rank < 0.0001). Dividing patients according to the mode CCI value (20.9) showed an estimated 5-year survival of 60 mo for a CCI below 20.9 vs 57 mo for a CCI above 20.9 (log-rank = 0.147). The univariate analysis did not show any association between individual complications and long-term survival. A multivariate analysis was carried out to analyse the possible influence of CCI, Charlson comorbidity index, BAR and hepatocellular carcinoma on survival. Only the CCI score showed significant influence on long-term survival.

CONCLUSION

A complicated postoperative period – well-defined by means of the CCI score – can influence not only short-term survival, but also long-term survival.

Vascular Resections for Pancreatic Ductal Adenocarcinoma: Vascular Resections for PDAC

BACKGROUND AND AIMS

It has become clear that vein resection and reconstruction for pancreatic ductal adenocarcinoma (PDAC) is the standard of care as supported by multiple guidelines. However, resection of large peri-pancreatic arteries remains debatable.

MATERIALS AND METHODS

This review examines the current state of vascular resection with curative intent for PDAC in the last 5 years. Herein, we consider venous (superior mesenteric vein, portal vein), as well as arterial (superior mesenteric artery, celiac trunk, hepatic artery) resection or both with or without reconstruction.

RESULTS

Improvement of multidrug chemotherapy has revolutionized care for PDAC that should shift traditional surgical thinking from an anatomical classification of resectability to a prognostic and biological classification.

CONCLUSION

The present review gives an overview on the results of pancreatectomy associated with vascular resection, with consideration of new perspectives offered by the availability of better systemic therapies.