Portal vein thrombosis (PVT) is a relatively common complication in patients with liver cirrhosis, but might also occur in absence of an overt liver disease. Several causes, either local or systemic, might play an important role in PVT pathogenesis. Frequently, more than one risk factor could be identified; however, occasionally no single factor is discernable. Clinical examination, laboratory investigations, and imaging are helpful to provide a quick diagnosis, as prompt treatment might greatly affect a patient's outcome. In this review, we analyze the physiopathological mechanisms of PVT development, together with the hemodynamic and functional alterations related to this condition. Moreover, we describe the principal factors most frequently involved in PVT development and the recent knowledge concerning diagnostic and therapeutic procedures. Finally, we analyze the implications of PVT in the setting of liver transplantation and its possible influence on patients' future prognoses.

ISRCTN10357435.

Background and study aims Colorectal endoscopic submucosal dissection (ESD) is still not widely used due to its technical difficulty and the risk of complications. Rescue therapies such as hybrid ESD (H-ESD) have been proposed for very difficult cases, as has underwater ESD (U-ESD). This study evaluated the safety and efficacy of H-ESD and U-ESD in difficult cases. Patients and methods The hospital charts of consecutive patients referred for colorectal ESD between January 2014 and February 2021 because they were considered difficult cases were retrospectively analyzed. The primary outcome of the study was en bloc resection rate; secondary outcomes were the rate of complete resection, procedure speed, and incidence of adverse events (AEs). Results Fifty-nine colorectal neoplasms were considered, 22 of which were removed by U-ESD and 37 by H-ESD. The en bloc resection rate in the U-ESD group was 100 %, while it was 59.5 % in the H-ESD group. Dissection speed was 17.7mm2/min in the U-ESD group and 8.3 mm2/min in the H-ESD group. The AE rate was low in the U-ESD group and moderately high during H-ESD (5 % and 21.6 %, respectively; and perforation rate 0 % and 10.8 %, respectively). Larger lesions were treated with U-ESD, while more fibrotic ones were treated with H-ESD. Conclusions U-ESD and H-ESD are both effective and safe techniques in difficult colorectal situations. U-ESD is particularly effective and fast for large lesions when it is not possible to obtain comfortable knife position, while H-ESD is more suitable for very fibrotic lesions.

When end stage liver disease occurs, liver transplantation is the only effective treatment available. In the past, liver transplantation was frequently accompanied by considerable bleeding complications and massive transfusion requirements, while only in recent years advances in operative management and a better understanding of the pathophysiology of coagulation have determined a better outcome for this major surgery. In addition, accumulating evidence shows that the overall haemostatic function in patients with cirrhosis facing liver transplantation may not be shifted towards a bleeding diathesis as traditionally believed, but that both bleeding episodes and thrombotic events may take place as major peri-and post-operative complications in patients undergoing liver surgery. The aim of this review paper is to offer an overview of recent developments that have gradually improved our understanding about the changes that may occur in the haemostatic system of patients undergoing liver transplantation, taking into account the best way to monitor them.