Olgierd Rowiński

Vascular complications after liver transplantation

Vascular complications following liver transplantation is reviewed based upon literature data and our own results. Our study conclusions are mostly based on literature data, because our center does not have the liver transplantation experience of other centers worldwide. Thus, we may conclude, that the number and character of complications does not differ from those reported by other centers. The enbloc technique used in liver harvesting minimizes the risk of arterial damage in case of vascular anomalies. Recipient retransplantation is the most effective treatment method in cases of hepatic arterial occlusion. Doppler ultrasound examinations are effective to monitor vascular blood flow in the transplanted liver.

Effects of the Correction of Renal Artery Stenosis on Blood Pressure, Renal Function and Left Ventricular Morphology

The aim of this study was to evaluate the effect of renal artery stenosis (RAS) correction in hypertensive patients on 24 h SBP, 24 h DBP, creatinine clearance (GFR), urinary albumin excretion (UAE) and LV morphology and mass (LVMI). A total of 61 hypertensive patients with RAS undergoing PTRA and/or surgical treatment entered the prospective study. The final analysis was done in 44 patients (age range 45.8 +/- 16.2 years) with RAS (atherosclerosis (ASC) 31 patients, fibromuscular dysplasia (FMD) 12 patients, arteritis 1 patient) who underwent PTRA (34 patients) or surgical treatment (10 patients) and presented no Doppler signs of restenosis (or a new stenosis) during 1-year observation. The pre-interventional assessment repeated after 6 and 12 months included ABPM, GFR, UAE and echocardiography. The results were analysed in the combined group (CG) and in according aetiology. 24 h SBP and 24 h DBP decreased in all groups 6 months post-intervention and did not change further. Cure of HT was observed in 35% and 29% of ASC patients at 6 and 12 months respectively; and in 58% of FMD patients. Failure rate at 12 months was 48% in ASC against 25% in FMD. The mean GFR in CG was higher 12 months after intervention. The increase in GFR was noted in 45% of patients, the decrease in 25% of patients at 12 months. Normal values of UAE were found in 71% of patients, pre- and post-intervention alike. Mean LVMI and number of patients with LVH in CG decreased already during the initial 6 months post-intervention and did not change further. In conclusion, correction of RAS leads to cure of or improved control of hypertension in the majority of the patients with FMD, but in the ASC group in about half of cases no BP cure or improvement was seen. The renal function was improved or stable in two-thirds of patients after revascularization. Successful renal revascularization was followed by regression of LVH, which was evident within 6 months post-intervention.

Computed Tomographic Angiography and Perfusion in the Diagnosis of Brain Death

INTRODUCTION According to Polish brain death (BD) criteria, instrumental confirmatory tests should be used in certain clinical situations, particularly any case for which clinical examinations seem inadequate. Electrophysiological tests are often unavailable. Therefore, cerebral perfusion testing is the method of choice with four-vessel digital subtraction angiography (DSA), the gold standard. Unfortunately, DSA is an expensive and invasive examination that requires an experienced neuroradiologist and the availability of an angiography suite. Recently, multirow computed tomographic devices became available, even in smaller hospitals in Poland. Despite this fact, computed tomographic angiography (CTA) and computed tomographic perfusion (CTP) are not accepted in BD diagnosis protocols in Poland because of limited experience and a lack of widely accepted criteria. In this situation, we started a multicenter trial to determine the accuracy of CTA and CTP to confirm BD. METHODS We examined 24 patients who fulfilled standard clinical BD criteria. We recognized the absence of brain perfusion in CTA examination following the criteria proposed by the French Society of Neuroradiology, namely, the absence of opacification of M4 middle cerebral artery segments (M4-MCA) and of deep cerebral veins. RESULTS In all of our patients, CTA showed absence of opacification of M4 segments and of deep cerebral veins. In addition, three patients had CTA showing weak opacification of A2 segments of the anterior cerebral artery (A2-ACA) and M2 or M3-MCA. Opacification of the basilar artery or of the posterior cerebral arteries was not noted in any case. In all patients, CTP revealed zero values of regional cerebral blood volume and regional cerebral blood flow. Conventional angiography confirmed cerebral circulatory arrest in all 24 cases. CONCLUSION CTA and CTP seem to be promising radiological examinations for the diagnosis of BD. They may be noninvasive alternatives to conventional cerebral angiography, and to the other instrumental confirmatory tests, that are unavailable or inadequate.

Non-Contrast-Enhanced Whole-Body Magnetic Resonance Imaging in the General Population: The Incidence of Abnormal Findings in Patients 50 Years Old and Younger Compared to Older Subjects

Purpose To assess and compare the incidence of abnormal findings detected during non-contrast-enhanced whole-body magnetic resonance imaging (WB-MRI) in the general population in two age groups: (1) 50 years old and younger; and (2) over 50 years old. Materials and Methods The analysis included 666 non-contrast-enhanced WB-MRIs performed on a 1.5-T scanner between December 2009 and June 2013 in a private hospital in 451 patients 50 years old and younger and 215 patients over 50 years old. The following images were obtained: T2-STIR (whole body-coronal plane), T2-STIR (whole spine-sagittal), T2-TSE with fat-saturation (neck and trunk-axial), T2-FLAIR (head-axial), 3D T1-GRE (thorax-coronal, axial), T2-TSE (abdomen-axial), chemical shift (abdomen-axial). Detected abnormalities were classified as: insignificant (type I), potentially significant, requiring medical attention (type II), significant, requiring treatment (type III). Results There were 3375 incidental findings depicted in 659 (98.9%) subjects: 2997 type I lesions (88.8%), 363 type II lesions (10.8%) and 15 type III lesions (0.4%), including malignant or possibly malignant lesions in seven subjects. The most differences in the prevalence of abnormalities on WB-MRI between patients 50 years old and younger and over 50 years old concerned: brain infarction (22.2%, 45.0% respectively), thyroid cysts/nodules (8.7%, 18.8%), pulmonary nodules (5.0%, 16.2%), significant degenerative disease of the spine (23.3%, 44.5%), extra-spinal degenerative disease (22.4%, 61.1%), hepatic steatosis (15.8%, 24.9%), liver cysts/hemangiomas (24%, 34.5%), renal cysts (16.9%, 40.6%), prostate enlargement (5.1% of males, 34.2% of males), uterine fibroids (16.3% of females, 37.9% of females). Conclusions Incidental findings were detected in almost all of the subjects. WB-MRI demonstrated that the prevalence of the vast majority of abnormalities increases with age.

Detection of active bile leak with Gd-EOB-DTPA enhanced MR cholangiography: Comparison of 20–25 min delayed and 60–180 min delayed images

OBJECTIVES The purpose of this study was to assess the value of contrast-enhanced magnetic resonance cholangiography (MRC) performed in different time delays after injection of gadoxetic acid disodium (Gd-EOB-DTPA) for the diagnosis of active bile leak. METHODS This retrospective analysis included Gd-EOB-DTPA enhanced MR images of 34 patients suspected of bile leak. Images were acquired 20-25 min after Gd-EOB-DTPA injection. If there was inadequate contrast in the bile ducts then delayed images after 60-90 min and 150-180 min were obtained. Results were correlated with intraoperative findings, ERCP results, clinical data, laboratory tests, and follow-up examinations. RESULTS Gd-EOB-DTPA enhanced MRC yielded an overall sensitivity of 96.4%, specificity of 100% and accuracy of 97.1% for the diagnosis of an active bile leak. The sensitivity of 20-25 min delayed MR images was 42.9%, of combined 20-25 min and 60-90 min delayed images was 92.9% and of combined 20-25 min, 60-90 min and 150-180 min delayed images was 96.4%. CONCLUSIONS Gd-EOB-DTPA enhanced MRC utilizing delayed phase images was effective for detecting the presence and location of active bile leaks. The images acquired 60-180 min post-injection enabled identification of bile leaks even in patients with a dilated biliary system or moderate liver dysfunction.

Treatment of Early Hepatic Artery Thrombosis After Liver Transplantation

INTRODUCTION Early hepatic artery thrombosis remains one of the major causes of graft failure and mortality in liver transplant recipients. It is the most frequent severe vascular complication after orthotopic liver transplantation (OLT) accounting for >50% of all arterial complications. Most patients need to be considered for urgent liver retransplantation. MATERIALS AND METHODS Among 911 OLTs in 862 from 1989 to 2011, we observed 23 cases (2.6%) of acute early hepatic artery thrombosis. Seventeen patients were qualified immediately for liver retransplantation, and 6 underwent endovascular therapies, including intra-arterial heparin infusion or percutaneous transluminal angioplasty with stent placement. RESULTS Among patients who were assigned to early liver retransplantation, 11/17 survived with 3 succumbling due to postoperative complications, including 1 portal vein thrombosis, and 3 succumbling on the waiting list. All patients who underwent endovascular therapy survived with an excellent result obtained in 1 who underwent treatment<24 hours after arterial thrombosis. In 2 patients we achieved a satisfactory result not requiring retransplantation, but 3 patients assigned to endovascular treatment>24 hours after arterial thrombosis needed to be reassigned to liver retransplantation because of poor results of endovascular treatment. CONCLUSIONS Endovascular treatment efforts should be made to rescue liver grafts through urgent revascularization depending on the patients condition and the interventional expertise at the transplant center, reserving the option of retransplantation for graft failure or severe dysfunction.

Plasma Fibrinogen as a Risk Factor for Restenosis after Percutaneous Transluminal Renal Angioplasty in Patients with Atherosclerotic Renal Artery Stenosis

Background In contrast to those for coronary restenosis, the data regarding the risk factors for renal restenosis are limited. Objective To evaluate potential humoral risk factors for restenosis after percutaneous transluminal renal angioplasty (PTRA). Methods We studied 27 patients aged 54 ± 10 years with atherosclerotic renal artery stenosis in a 1-year prospective follow-up. Restenosis (confirmed by angiography) occurred in eight patients 1–6 months after PTRA. We detected no Doppler ultrasound evidence of restenosis in 19 patients throughout 1 year. Blood studies were done before PTRA for all patients, at the time of diagnosis of restenosis and, for those without restenosis, after 1 year, including determinations of fibrinogen, lipids, platelets and leukocytes. Results The mean level of fibrinogen in patients who experienced restenosis was higher than that in those who did not (450 ± 150 mg% versus 337 ± 57 mg%, P < 0.01) and remained unchanged for both groups during follow-up. The other parameters did not differ between the groups before PTRA and did not change over time, with the exception of platelet count in patients who did not experience restenosis, which had decreased from 253 ± 93 G/l to 200 ± 63G/l (P < 0.01) 1 year after PTRA. The logistic multiple regression analysis disclosed that an increment of fibrinogen level by 100 mg% was linked with an odds ratio for restenosis of 3.2 (95% confidence interval 1.1–9.8). Conclusions Restenosis was associated with higher than normal levels of fibrinogen before PTRA. A high plasma fibrinogen level might play a role in the development of restenosis after PTRA.

MR Imaging of Pulmonary Nodules: Detection Rate and Accuracy of Size Estimation in Comparison to Computed Tomography.

Objective The aims of this study were to assess the sensitivity of various magnetic resonance imaging (MRI) sequences for the diagnosis of pulmonary nodules and to estimate the accuracy of MRI for the measurement of lesion size, as compared to computed tomography (CT). Methods Fifty patients with 113 pulmonary nodules diagnosed by CT underwent lung MRI and CT. MRI studies were performed on 1.5T scanner using the following sequences: T2-TSE, T2-SPIR, T2-STIR, T2-HASTE, T1-VIBE, and T1-out-of-phase. CT and MRI data were analyzed independently by two radiologists. Results The overall sensitivity of MRI for the detection of pulmonary nodules was 80.5% and according to nodule size: 57.1% for nodules ≤4mm, 75% for nodules >4-6mm, 87.5% for nodules >6-8mm and 100% for nodules >8mm. MRI sequences yielded following sensitivities: 69% (T1-VIBE), 54.9% (T2-SPIR), 48.7% (T2-TSE), 48.7% (T1-out-of-phase), 45.1% (T2-STIR), 25.7% (T2-HASTE), respectively. There was very strong agreement between the maximum diameter of pulmonary nodules measured by CT and MRI (mean difference -0.02 mm; 95% CI –1.6–1.57 mm; Bland-Altman analysis). Conclusions MRI yielded high sensitivity for the detection of pulmonary nodules and enabled accurate assessment of their diameter. Therefore it may be considered an alternative to CT for follow-up of some lung lesions. However, due to significant number of false positive diagnoses, it is not ready to replace CT as a tool for lung nodule detection.

Pancreatic lipoma: An incydentaloma which can resemble cancer - analysis of 13 cases studied with CT and MRI.

Summary Background: The purpose of this article is to present computed tomography (CT) and magnetic resonance imaging (MRI) findings of rare pancreatic lipomas. Material/Methods: The analysis covered 13 patients (7 men and 6 women, aged 47–88, average: 65.6 years), with 13 pancreatic lipomas, whose cases constituted the basis for 10 contrast-enhanced CT and 5 MRI studies. Results: Lipomas measured from 6 mm to 32 mm (average 12.8 mm) and were located in the pancreatic head (n=7), body (n=2), tail (n=3) and uncinate process (n=1). Most lesions (n=11) were homogenous, well-circumscribed. On contrast-enhanced CT scans, macroscopic fat (<−30 HU) was present in 9 lipomas. In one case (10 mm lesion) the density was −20 HU and the lesion was poorly circumscribed with septations, which altogether made it difficult to precisely characterize its contents. On MR scans fat was demonstrated in all studied cases (n=5). Conclusions: Lipomas are rare, small, homogenous and well-circumscribed pancreatic tumours. The most important feature, decisive for the diagnosis and distinguishing them from pancreatic carcinoma, is detection of fatty tissue on CT and MR scans. In these cases differential diagnosis includes other rare fatty tumours of the pancreas (focal fatty infiltration, teratoma, liposarcoma).

Changes of size and shape of small, unruptured intracranial aneurysms in repeated computed tomography angiography studies.

Introduction Unruptured intracranial aneurysms (UIAs) are frequently detected in noninvasive imaging studies such as computed tomography angiography (CTA) or magnetic resonance angiography (MRA). If small, UIAs are observed in these modalities in order to detect growth or shape change, but there are many questions about proper protocol of the follow-up. Aim To assess changes of small (< 7 mm) UIAs dome size and shape in repeated CTA studies as predictors of growth and rupture. Material and methods One hundred and ten UIAs (10 posterior circulation) in 70 patients (55 women) were observed, with a cumulative observation time of 333.32 years. Aneurysms’ dome and neck perpendicular dimensions were measured in the first and the last CTA study at least twice with the developed application. Confidence intervals (CI) for measurements and dome shape parameters were calculated. For aneurysms ruptured during follow-up intermediate studies were analyzed. Patients’ clinical information was recorded. The aneurysm growth detection algorithm integrated CI and spatial resolution of the CT scanner. Results Twenty-three aneurysms increased in volume, 10 in height and 14 in dome width. Volume increased in 90% of cases of height and 93% of width increase. Posterior circulation aneurysms grew faster than anterior ones (p < 0.003), but calculated time to significant size increase (eT) did not differ between the groups due to higher CI in the posterior circulation. Analysis of eT with Kaplan-Meier curves showed that 75% of growing aneurysms could be detected in the first 3 years of observation. During the follow-up 3 aneurysms bled, and they grew faster than other growing aneurysms. Two of the bleeding aneurysms formed daughter sacs. Conclusions Dome volume assessment is superior to single dimension assessment in aneurysm growth detection. Confidence intervals assessment helps to avoid overestimation of growth. Seventy-five percent of growing aneurysms could be detected in the first 3 years of observation. Daughter sac formation and fast increase in size are strong predictors of aneurysm rupture.