Francesco Doenz

Multi-phase post-mortem CT angiography: development of a standardized protocol

The objective of this work was to develop an easily applicable technique and a standardized protocol for high-quality post-mortem angiography. This protocol should (1) increase the radiological interpretation by decreasing artifacts due to the perfusion and by reaching a complete filling of the vascular system and (2) ease and standardize the execution of the examination. To this aim, 45 human corpses were investigated by post-mortem computed tomography (CT) angiography using different perfusion protocols, a modified heart–lung machine and a new contrast agent mixture, specifically developed for post-mortem investigations. The quality of the CT angiographies was evaluated radiologically by observing the filling of the vascular system and assessing the interpretability of the resulting images and by comparing radiological diagnoses to conventional autopsy conclusions. Post-mortem angiography yielded satisfactory results provided that the volumes of the injected contrast agent mixture were high enough to completely fill the vascular system. In order to avoid artifacts due to the post-mortem perfusion, a minimum of three angiographic phases and one native scan had to be performed. These findings were taken into account to develop a protocol for quality post-mortem CT angiography that minimizes the risk of radiological misinterpretation. The proposed protocol is easy applicable in a standardized way and yields high-quality radiologically interpretable visualization of the vascular system in post-mortem investigations.

Nonoperative Management of Traumatic Splenic Injuries: Is There a Role for Proximal Splenic Artery Embolization?

OBJECTIVE The objective of our study was to evaluate our experience with transcatheter proximal (i.e., main) splenic artery embolization (TPSAE) in the nonsurgical management of patients with grade III-V splenic injuries, according to the American Association for the Surgery of Trauma (AAST) guidelines, and patients with splenic injuries associated with CT evidence of active contrast extravasation or blush (or cases meeting both criteria). MATERIALS AND METHODS The records of patients with traumatic splenic injuries admitted during a 52-month period were retrospectively reviewed for patient age and sex, mechanism of injury, injury severity score (ISS), RBC transfusion requirements, AAST splenic injury CT grade, presence of active contrast extravasation or blush on CT examination, and amount of hemoperitoneum on CT examination. Demographics, CT findings, transfusion requirements, and outcome were compared using the Students t test or chi-square test in patients undergoing standard nonoperative management and nonoperative management TPSAE-that is, TPSAE followed by nonoperative management. RESULTS Of the 79 identified patients with splenic trauma, 67 were managed nonoperatively. Thirty-seven patients (28 men, nine women; mean age, 40 years; mean ISS, 28.8) underwent nonoperative management TPSAE and 30 patients (27 men, three women; mean age, 37 years; mean ISS, 25.1) underwent nonoperative management. Age, sex, and ISS were not significantly different between the two groups. TPSAE was always technically feasible. Splenic injuries were significantly more severe in the nonoperative management TPSAE group than in the nonoperative management group with respect to the mean splenic injury AAST CT grade (3.7 vs 2, respectively; p < 0.0001), active contrast extravasation or blush (38% [14/37] vs 3% [1/30], respectively; p = 0.0005), and hemoperitoneum grade (1.6 vs 0.8, respectively; p = 0.0006). Secondary splenectomy rate was lower in the nonoperative management TPSAE group (2.7% [1/37] vs 10% [3/30]). No procedure-related complications were encountered during early and delayed clinical follow-up. CONCLUSION TPSAE is a feasible and safe adjunct to observation in the nonoperative management of severe traumatic splenic injuries. The secondary splenectomy rate using nonoperative management TPSAE (2.7%) is among the lowest reported despite a selection of severe injuries.

Clinical experience with retrievable Günther Tulip vena cava filters.

Purpose: To report clinical experience with retrievable Günther Tulip filters from implantation to retrieval and their status in nonretrieved situations. Methods: Seventy-five Günther Tulip filter implantations were performed in 71 patients (43 women; mean age 55 years). Indications for filter placement were pulmonary embolism (PE) or iliofemoral deep vein thrombosis (DVT) in patients with a contraindication to anticoagulation (43, 61%) or perioperative PE prophylaxis (28, 39%) in patients with confirmed iliofemoral DVT. Retrieval procedures were planned for each patient. Patients with nonretrieved filters were followed with plain radiography and duplex sonography. Results: Technical success of filter insertion was 97.3% (73/75). Eighteen (25%) patients died from unrelated causes prior to retrieval attempts, and 6 other patients were too critically ill for a retrieval procedure. Of 49 (67%) planned retrieval attempts, 14 (19%) filters could not be removed owing to large trapped thrombi. The mean implantation period for the 35 (48%) retrieved filters was 8.2 days (range 1–13). Delivery tilt was observed in 12 (16%) filters and during retrieval attempts in 1 more case. For 9 nonretrieved filters, tilt and migration were observed in 22% at a mean follow-up of 30 months, but no venous thrombosis was assessed. Conclusions: Our data confirm the clinical efficacy of the Günther Tulip filter during implantation and the feasibility of its retrieval. Further long-term follow-up should be conducted on nonretrieved filters to confirm our results.

Portal vein embolization with N-butyl cyanoacrylate before partial hepatectomy in patients with hepatocellular carcinoma and underlying cirrhosis or advanced fibrosis.

PURPOSE To describe the safety, complications, and liver regeneration associated with the left liver after embolization of the right portal vein (PV) in patients with hepatocellular carcinoma (HCC) developed in the setting of advanced liver fibrosis and cirrhosis. MATERIALS AND METHODS Forty patients (31 men, nine women; mean age, 62 years) with HCC underwent PV embolization over a 4-year period. Embolization was performed from a left PV percutaneous access with use of n-butyl cyanoacrylate (NBCA) mixed with iodized oil. Computed tomography (CT) volumetry was performed before and 1 month after PV embolization to measure the left lobe volume as well as the functional liver ratio defined by the ratio between the left lobe and the total liver volume minus tumoral volume. PV pressure and liver enzyme levels were compared before and 1 month after the procedure and complications were registered. Factors potentially affecting regeneration (age, sex, diabetes, chemoembolization, functional liver ratio before PV embolization, and Knodell histologic score) were evaluated by one-way and stepwise regression analysis. RESULTS PV embolization could be achieved successfully in all cases. Two patients had partial PV thrombosis on the 1-month follow-up CT and two patients developed transient ascites after PV embolization. The left lobe volume increase was 41% +/- 32% after PV embolization and the functional liver ratio increased from 28% +/- 10% to 36% +/- 10% (P < .0001). Hypertrophy of the left lobe was greater in patients with a low functional liver ratio before PV embolization and those with an F3 fibrosis score. Other factors had no influence on left lobe regeneration. CONCLUSION PV embolization with use of NBCA is feasible in patients with advanced fibrosis and cirrhosis. Hypertrophy of the left lobe of the liver after PV embolization has a statistically significant correlation with lower functional liver ratio and lower degrees of fibrosis.

Evaluation of postmortem MDCT and MDCT-angiography for the investigation of sudden cardiac death related to atherosclerotic coronary artery disease

The goal of this study was to evaluate the diagnostic value of postmortem multi-computed tomography (MDCT) and MDCT-angiography for sudden cardiac deaths related to ischemic heart disease. Twenty three cases were selected based on clinical history and the results of native MDCT, multiphase post-mortem CT-angiography and conventional autopsy were compared. Radiological examination showed calcification of coronary arteries in 78% of the cases, most of which were not detailed at autopsy. MDCT-angiography allowed better visualization of the coronary arteries than MDCT and permitted the evaluation of stenoses and occlusions. Of the 14 cases of coronary thrombosis detected at conventional autopsy, 11 were visible as stop of perfusion with CT-angiography and three were found to be partly perfused. One case had an old thrombosis with collateral circulation. One case had a coronary artery postmortem clot found with MDCT-angiography. Coronary artery calcifications are more easily detected and documented with radiological examination than with conventional autopsy. MDCT is of limited diagnostic value for ischemic heart disease. MDCT-angiography, when correctly interpreted, is a reasonable tool to view the morphology of coronary arteries, rule out significant coronary artery stenoses, identify occlusions and direct sampling for histological examination.

Detection of hemorrhage source: The diagnostic value of post-mortem CT-angiography

The aim of this study was to compare the diagnostic value of post-mortem computed tomography angiography (PMCTA) to conventional, ante-mortem computed tomography (CT)-scan, CT-angiography (CTA) and digital subtraction angiography (DSA) in the detection and localization of the source of bleeding in cases of acute hemorrhage with fatal outcomes. The medical records and imaging scans of nine individuals who underwent a conventional, ante-mortem CT-scan, CTA or DSA and later died in the hospital as a result of an acute hemorrhage were reviewed. Post-mortem computed tomography angiography, using multi-phase post-mortem CTA, as well as medico-legal autopsies were performed. Localization accuracy of the bleeding was assessed by comparing the diagnostic findings of the different techniques. The results revealed that data from ante-mortem and post-mortem radiological examinations were similar, though the PMCTA showed a higher sensitivity for detecting the hemorrhage source than did ante-mortem radiological investigations. By comparing the results of PMCTA and conventional autopsy, much higher sensitivity was noted in PMCTA in identifying the source of the bleeding. In fact, the vessels involved were identified in eight out of nine cases using PMCTA and only in three cases through conventional autopsy. Our study showed that PMCTA, similar to clinical radiological investigations, is able to precisely identify lesions of arterial and/or venous vessels and thus determine the source of bleeding in cases of acute hemorrhages with fatal outcomes.

Life-threatening vascular complications after central venous catheter placement

Abstract. The purpose of this retrospective study was to report 11 cases of severe vascular complications after central venous catheter misplacement. For each patient, data collection included body mass index, the diagnosis at admission, the site of the procedure, the type of catheter, coagulation parameters, the imaging modalities performed and the applied treatment. Eight patients had a lesion of the subclavian artery. Brachiocephalic vein perforations were assessed in three more patients. All patients had a chest roentgenogram after the procedure, six a CT examination, and four an angiographic procedure. Seven patients had a body mass index above 30, and 5 patients had coagulation disorders prior to the procedure. Seven patients were conservatively managed, 2 patients died despite resuscitation, 1 patient was treated with a stent graft, and one by superselective embolization. Subclavian or jugular vein temporary catheter positioning is a practical approach. Identification of any iatrogenic perforation of the subclavian artery or central veins urges obtainment a chest roentgenogram and, when required, a chest CT, selective angiograms or venograms. Body mass index superior to 30, previous unsuccessful catheterization attempts, and coagulation factor depletion seemed to account for risk factors. Recognition of clinical and radiological complications is mandatory.

Interventional radiology in the management of complications after liver transplantation

The arrival of new surgical transplantation techniques, such as split living donor or auxiliary liver transplantation, have increased the incidence of vascular and biliary complications. The causes, symptoms, and diagnostic modalities of arterial, portal caval, and biliary complications are detailed. Interventional techniques, such as balloon angioplasty and stent placement in the arterial and portal tree, as well as biliary interventional techniques, are discussed.

Computed tomographic angiography in acute pulmonary embolism: do we need multiplanar reconstructions to evaluate the right ventricular dysfunction?

Purpose: To compare the indices of right ventricular dysfunction (RVD) obtained from axial transverse images with those derived from the reconstructed 4-chamber and short-axis views in patients with acute pulmonary embolism (PE). Materials and Methods: Eighty-eight patients with acute PE were retrospectively enrolled. For each patient, axial transverse images and reconstructed 4-chamber and short-axis views were reviewed. Measurements of the ratios of right ventricle to left ventricle (RV/LV) diameters and RV/LV areas were then obtained from all series. Values derived from each method were compared and correlated to arterial obstruction index. Results: In the studied cohort, RV/LV diameters and RV/LV areas obtained from axial transverse images and the reconstructed 4-chamber views were not statistically different. In contrast, a statistically significant difference was observed between the values of RV/LV areas derived from both axial transverse and 4-chamber views and those obtained from short-axis views (P < 0.0001). There was a weak to moderate correlation between both RV/LV diameters and RV/LV areas and the computed tomographic obstruction index. However, when the study cohort was divided into 3 subgroups with an arterial obstruction index of less than 15% (n = 26), 15% to 30% (n = 21), and greater than 30% (n = 41), those who had values greater than 30% revealed the highest correlation with the indices of RVD. Conclusions: In patients with acute PE, the indices of RVD derived from axial transverse images and the reconstructed 4-chamber views yield comparative values. Given the simplicity of the former analysis, it should be taken into consideration for risk stratification in acute PE.

Indications for and limitations of portal vein embolization before major hepatic resection for hepatobiliary malignancy

Portal vein embolization is a promising adjunctive tool in liver surgery; however, the understanding of liver regeneration and PVE is still in its infancy. Refinement in patient selection criteria and methods to evaluate hepatic hypertrophy and function should increase the potential indications for PVE and expand the field of major liver surgery.