We spoke to Dr. Calandri to get hear more about his lecture on vascular transplantation complications.
Vascular transplantation complications
Diagnostic radiology roots, multi-disease knowledge, multi-disciplinary approach
These key points can well describe the fundamentals of the future of Interventional radiology. But, from another more fascinating perspective, they can identify the cornerstones of a specific setting, the role of interventional radiology in the management of vascular complications of liver transplantation. And this is why the IR approach to liver transplantation complications, with historical papers published a few years after the first liver transplant in 1963, can be considered the archetype of the IR contribution in many other scenarios, such as vascular or oncology.
Diagnostic radiology roots
As our interventional mentors taught us, everything starts from an adequate diagnostic work-up. Consistently, a successful management of vascular complications starts from their early detection through regular doppler ultrasound and CT scans. Doppler ultrasound can be easily performed in the operating room, in the ICU and then during follow up in the radiology department. A precise analysis of the arterial flow can give information on arterial stenosis including peak velocity, resistive index and tardus parvus waveform.
Multiphase CT including arterial phase can precisely identify the site of the arterial stenosis and it is fundamental before any surgical, transarterial or percutaneous interventions. Furthermore, timing is a relevant factor both for the detection of stenosis and thrombosis, both for the hepatic artery and portal and hepatic veins. Interventional radiologists, before moving to the angio suite, should be well aware of the precise setting in which they are asked to operate.
A versatile knowledge of different vascular districts is of paramount importance for the correct management of liver transplant complications, being aware that codependent modifications of arterial, portal, and hepatic vein flows can occur during follow-up. Furthermore, a correct approach to vascular complications should always include a deep knowledge of potential biliary complications. The interaction between arterial damage and biliary complications is well-known and relevant, since up to 80% of biliary complications are related to arterial stenosis or thrombosis.
Arterial flow stop to the transplanted organ due to severe stenosis or thrombosis requires varying treatments, depending on the timing of the onset of the complication. Early complications are more prone to re-surgery, whereas late-onset suggests a more cautious approach, including a watch and wait strategy and angioplasty or stenting, depending on the site and extension.
Portal vein stenosis is a very rare complication, slightly more common in split grafts, specifically pediatric ones. The increased incidence in pediatric split grafts is due to size mismatch between the donor’s and the patient’s portal vein. Percutaneous transluminal angioplasty is a valuable therapeutic option. However, restenosis is frequent, especially in children, due to elastic recoil and anatomical changes during growth. Stenting can be an option in these cases; the indication of bare metal stent placement should always be carefully evaluated due to the high risk of interference in case of retransplantation.
Inferior vena cava stenosis occurs in <1% of liver transplanted patients. The main causes of stenosis immediately after transplantation are size mismatch, twisting, dissection, or technical issues. Late stenosis, however, is most often due to perivascular fibrosis, but it may also be caused by compression or twisting of the graft.
Treatment of inferior vena cava stenosis will require repeated balloon angioplasty and ultimately stent placement; however, the risk of stent migration, malposition, or occlusion of the hepatic vein ostium should be always considered.
As described above, the interventional radiology portfolio for the treatment of liver transplant complications today is diverse and enriched with new devices. Techniques have improved enormously in recent years, especially in the venous field.
However, the best therapeutic approach should always consider the high need for organ preservation and should never interfere with the possibility of retransplantation. Furthermore, in a real multidisciplinary setting, surgery and medical care should always be carefully evaluated as other valuable options.
In conclusion, an optimal diagnostic phase, a versatile knowledge of the different complications (arterial, venous, but also biliary), and the awareness of the many available treatments are the cornerstones for IR practice in the present and the future of liver transplantation.
Città della Salute e della Scienza Hospital, Torino/IT
Dr. Marco Calandri is an assistant professor and lecturer of radiology at University of Torino, working as a diagnostic and interventional radiologist at “Città della Salute e della Scienza” Hospital in Torino. He obtained his medical degree cum laude in 2011 and completed his residency in 2017. During his residency he visited, as an observer and as a visiting resident, the interventional radiology department of the Institut Gustave Roussy (Villejuif, Fr) and MD Anderson Cancer Center (Houston, US). He is an active member of the Italian Society of Radiology (SIRM), European Society of Radiology (ESR), and Cardiovascular and Interventional Radiological Society of Europe (CIRSE). He is the authorized representative for his center for the IASIOS accreditation. In his professional and scientific work, Dr. Calandri has been focussing on interventional oncology, with a specific emphasis to thermal ablation of colorectal liver metastases, and liver transplantation. He has authored and co-authored more than 50 articles in peer-review journals, is co-author of book chapters, and has given over 60 invited lectures at national and international meetings.
- Interventional radiology in the management of the liver transplant patient. Thornburg B, Katariya N, Riaz A, Desai K, Hickey R, Lewandowski R, Salem R. Liver Transpl. 2017 Oct;23(10):1328-1341. doi: 10.1002/lt.24828.
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- Shibata T, Itoh K, Kubo T, Maetani Y, Shibata T, Togashi K,Tanaka K. Percutaneous transhepatic balloon dilation of portal venous stenosis in patients with living donor liver transplantation.Radiology 2005;235:1078-1083.