Vascular complications following liver transplantation

Interventional treatment for portal vein complications utilizing a hybrid operating room after liver transplantation

BACKGROUND

Vascular complications after liver transplantation (LT) can be lethal and require immediate treatment to prevent graft failure. Nowadays, with interventional radiology (IR), approaches such as the percutaneous transhepatic (PTH) and transileocolic venous (TIC), have become major treatment options. We reviewed the safety and efficacy of a hybrid operating room (OR) for portal vein complications after LT.

METHODS

Patients who underwent IR for post-LT vascular complications in the hybrid OR from May 2014 to May 2022 were enrolled. Patients who underwent post-LT IR in conventional angiography rooms were excluded.

RESULTS

Nine patients developed portal vein complications; eight after living donor LT and one after deceased donor LT. Six patients had portal vein stenosis, two had portal vein thrombosis, and one had both. In the hybrid OR, PTH and TIC were used in five and three cases, respectively. The Rendezvous technique was used in one case. Angioplasty was performed in all patients. A stent was placed in four patients. The portal venous pressure gradient across the stenotic site significantly decreased after IR (P &= 0.031). The IR success rate in the hybrid OR was 100%.

CONCLUSION

The hybrid OR enables us to accomplish IR for post-LT vascular complications safely and effectively.

Portal vein complications and outcomes following pediatric liver transplantation: Data from the Society of Pediatric Liver Transplantation

Children who undergo liver transplantation are at risk for portal vein complications (PVCs) including thrombosis (PVT) and stenosis (PVS). Using multicenter data from the Society of Pediatric Liver Transplantation, we analyzed the prevalence, timing, and risk factors for PVC following a first liver transplantation, and assessed the potential impact of PVC on patient outcomes. Our cohort included 4278 patients, of whom 327 (7.6%) developed PVC. Multivariate analysis discovered several factors independently associated with PVC: younger recipient age, lower weight at time of transplantation, diagnosis of biliary atresia (BA), receiving a technical variant graft (TVG), warm ischemia time over 3 h, PVT in the recipient's pretransplantation native liver, and concurrent hepatic artery thrombosis (all p < 0.05). Subgroup analysis of those with BA found higher prevalence in patients transplanted at less than 2 years of age and those with TVGs. There was no difference in PVC prevalence among patients with BA with vs. without prior Kasai portoenterostomy. Most PVT (77.7%) presented within 90 days after transplantation. Patients with PVC had a higher risk of graft failure (23.9% vs. 8.3%; adjusted hazard ratio [HR], 3.08; p < 0.001) and a higher risk of death (16.4% vs. 8.9%; adjusted HR, 1.96; p = 0.01). Recurrence after retransplantation was similar to the overall prevalence in the cohort (8.2%). Our results recognize the common occurrence of PVC following pediatric liver transplantation, describe independently associated risk factors, and determine that patients with PVC have worse outcomes. Further studies are needed to improve PVC prevention, detection, and management strategies.

Effect of Blood Product Resuscitation on the Pharmacokinetics of Ampicillin-Sulbactam during Orthotopic Liver Transplantation

Background: Ampicillin-sulbactam is a piperacillin-tazobactam-sparing alternative antibiotic administered as surgical prophylaxis during orthotopic liver transplant (OLT), but limited data are available describing its pharmacokinetics and impact of blood product resuscitation. The purpose of this study was to determine the intra-operative pharmacokinetics of ampicillin-sulbactam in patients during OLT and evaluate the effects of blood resuscitation on exposure. Patients and Methods: This was a pharmacokinetic study in 10 OLT patients receiving ampicillin-sulbactam surgical prophylaxis. A 5,000-patient Monte Carlo simulation was conducted to identify optimal ampicillin-sulbactam regimens. Linear regression assessed association between blood product administration and ampicillin exposures. Results: Ampicillin and sulbactam concentrations best fitted two-compartment models. Mean ampicillin pharmacokinetic parameters were central compartment volume (V_c): 6.9 ± 2.0 L, clearance (CL): 26.6 ± 18.4 L/h, and inter-compartmental rate constants (k₁₂ and k₂₁): 4.8 ± 2.6 and 2.3 ± 1.4 h^-1. Sulbactam pharmacokinetic parameters were V_c: 8.1 ± 2.7 L, CL: 26.1 ± 7.4 L/h, k₁₂ and k₂₁: 4.9 ± 1.0 and 2.8 ± 1.1 h^-1. Participants received between 500 and 23,642 mL of total blood product. No statistical relations were observed between blood product administration and exposures (R² 0.00-0.26). Ampicillin-sulbactam 2/1 g every two hours and 2/1 g bolus followed by 6/3 g continuous infusion provided acceptable probability of target attainment up to minimum inhibitory concentrations (MICs) of 16 and 32 mcg/mL, respectively. Conclusions: High and frequent ampicillin-sulbactam doses are required to maintain 100% fT > MIC at relevant MICs during OLT and no impact of blood product resuscitation was observed on ampicillin exposure. These are the first data available to guide ampicillin-sulbactam dosing in patients undergoing OLT.

Outcome of prolonged acute vena cava occlusion after iatrogenic transection and repair in a dog

A 12-year-old castrated male Airedale terrier dog was diagnosed with a hepatocellular carcinoma in the right medial liver lobe. During tumor resection, inadvertent stapling and transection of the caudal vena cava occurred. Complete caval occlusion was required for 18 minutes and primary anastomosis was completed. The dog received 2 blood transfusions and developed mild pelvic limb edema after surgery. Computed tomography evaluation 9 months after surgery showed collateral circulation and suspected stricture of the vena cava with an absence of clinical effect. The dog remained alive and asymptomatic more than 1 year after surgery.

Role of Doppler Sonography in Early Detection of Splenic Steal Syndrome

OBJECTIVES

To retrospectively investigate the role of Doppler sonography in the early detection of splenic steal syndrome.

METHODS

Fifty cases of splenic steal syndrome after orthotopic liver transplantation were identified. A control group was matched to the splenic steal syndrome group. Information was collected about the clinical presentation, liver enzyme levels, Doppler sonographic results, and follow-up after patients underwent splenic artery embolization.

RESULTS

A persistent hepatic arterial diastolic reversal waveform was observed in 25 patients with splenic steal syndrome versus 0 control patients. The mean hepatic arterial resistive index (RI) values ± SD were 0.95 ± 0.09 in patients with splenic steal syndrome and 0.80 ± 0.10 in control patients (P < .0001). One week after orthotopic liver transplantation, the area under the receiver operating characteristic curve for the RI was 0.884 (95% confidence interval, 0.793-0.975; P = .001) for splenic steal syndrome diagnosis. After splenic artery embolization, there was normalization of the reversal waveform, with an average RI of 0.77 ± 0.11 (P < .0001).

CONCLUSIONS

Dynamic changes in the hepatic arterial waveform and RI are keys to detecting splenic steal syndrome with Doppler sonography.

Iatrogenic-related transplant injuries: the role of the interventional radiologist

As advances in surgical techniques and postoperative care continue to improve outcomes, the use of solid organ transplants as a treatment for end-stage organ disease is increasing. With the growing population of transplant patients, there is an increasing need for radiologic diagnosis and minimally invasive procedures for the management of posttransplant complications. Typical complications may be vascular or nonvascular. Vascular complications include arterial stenosis, graft thrombosis, and development of fistulae. Common nonvascular complications consist of leaks, abscess formation, and stricture development. The use of interventional radiology in the management of these problems has led to better graft survival and lower patient morbidity and mortality. An understanding of surgical techniques, postoperative anatomy, radiologic findings, and management options for complications is critical for proficient management of complex transplant cases. This article reviews these factors for kidney, liver, pancreas, islet cell, lung, and small bowel transplants.

Incidence, management, and results of hepatic artery stenosis after liver transplantation in the era of donor to recipient match

INTRODUCTION

Hepatic artery stenosis (HAS) is an important complication after liver transplantation. However, studies are not conclusive in terms of definition, incidence, best treatment, and timing of intervention. The aim of this study was to evaluate the incidence of SSHA that occurred in a single center over the past 12 years, pointing out diagnostic and therapeutic strategies.

METHODS

The incidence of HAS was reviewed in 258 liver transplant recipients between January 1999 and December 2011. All patients underwent Doppler ultrasound (DUS) at fixed times. Multidetector computed tomographic angiography (MDCTA) was performed to confirm the DUS findings.

RESULTS

HAS occurred in 23 cases (9.3%). In all cases diagnosis was performed by DUS resulting in a sensitivity of 100% and a specificity of 99.6%. Based on DUS and MDCTA data integration, in 10 cases we adopted the "wait and see" strategy, whereas 13 patients underwent interventional radiology techniques.

CONCLUSION

DUS monitoring is efficacious in the diagnosis of HAS after liver transplantation. Interventional radiology procedures are safe and efficacious.

The Role of Interventional Radiology in Treating Complications following Liver Transplantation

Liver transplantation (LT) is used to treat both adult and pediatric patients with end-stage liver disease or acute liver failure. It has become more prevalent as both the surgical technique and postoperative care have improved resulting in a reduced morbidity and mortality. As a result, there are more patients surviving longer after liver transplantation. Despite this, there remain serious complications from the procedure that have a significant outcome on the patient and may result in retransplantation. At the same time, there have been significant advances in the field of interventional radiology both in terms of technology and how these apply to the patients. In this paper, we review the commonest complications, diagnostic tests, and interventional management options available.

Preliminary results of supra-hepatic intraaortic perfusion with nitroglycerin for patients with significant hepatic dysfunction

BACKGROUND

Preoperative hepatic dysfunction is a risk factor for postoperative fulminant hepatic failure and death. We noted persistent hepatic artery vasospasm in patients dying of postoperative hepatic failure. We hypothesized that an intra-aortic vasodilator such as nitroglycerin could attenuate vasospasm and prevent hepatic failure.

METHODS

Nineteen consecutive patients with significant preoperative hepatic dysfunction underwent cardiac surgery using cardiopulmonary bypass with continuous infusion of intra-aortic nitroglycerin via a catheter placed above the celiac axis. Serial hepatic artery Doppler studies were done perioperatively with and without the nitroglycerin infusion on. Hepatic artery Doppler, hepatic artery size, alterations in liver function and serum creatinine, and outcomes were noted. Survival was compared to the Euroscore and a hepatic risk score that was based on a historical cohort and reported literature.

RESULTS

One patient could not be weaned off cardiopulmonary bypass. In the remaining 18 patients, reversible hepatic arterial vasospasm was noted, and this persisted at 24 hours in 12 patients and 48 hours in 7 patients. All patients had resolution of vasospasm at 72 hours. Serial paired hepatic artery diameter measurements showed a significant difference (P < .001). There was a significant reduction in mortality (5.2 %) compared to historical control and predicted mortality (logistic Euroscore 37.4%, P = .023). None of the survivors had a significant alteration in hepato-renal function.

CONCLUSION

Intra-aortic nitroglycerin can attenuate hepatic arterial vasospasm induced by cardiopulmonary bypass and preserve hepatic function. This may reduce the risk associated with cardiopulmonary bypass and surgery in patients with liver dysfunction.