Pierre Perreault

Patency of stents covered with polytetrafluoroethylene in patients treated by transjugular intrahepatic portosystemic shunts: long-term results of a randomized multicentre study.

An 80% dysfunction rate at 2 years limits the use of transjugular intrahepatic portosystemic shunts (TIPS) in the treatment of complications of portal hypertension. The use of covered stents could improve shunt patency; however, long‐term effect and safety remain unknown. Eighty patients randomized to be treated by TIPS either with a covered stent (Group 1) or an uncovered prosthesis (Group 2) were followed‐up for 2 years. Doppler US was performed every 3 months. Angiography and portosystemic pressure gradient measurement were performed every 6 months or whenever dysfunction was suspected. Actuarial rates of primary patency in Groups 1 and 2 were 76% and 36% respectively (P=0.001). Clinical relapse occurred in four patients (10%) in Group 1 and 12 (29%) in Group 2 (P<0.05). Actuarial rates of being free of encephalopathy were 67% in Group 1 and 51% in Group 2 (P<0.05). Probability of survival was 58% and 45% at 2 years, respectively, in Groups 1 and 2 (NS). The mean Child–Pugh score improved only in Group 1 (from 8.1±1.6 to 7±2.2 at 2 years –P<0.05). We also compared the Doppler‐US parameters between patent and dysfunctioning shunts. In patent shunts, the mean velocity within the portal vein was significantly higher but the performance of Doppler‐US was not accurate enough to predict shunt dysfunction. In conclusion, the improvement in TIPS patency by using covered prostheses is maintained over time with a decreased risk of encephalopathy, while the risk of death was not increased.

The 6-F nitinol TrapEase inferior vena cava filter: Results of a prospective multicenter trial

PURPOSEnThe authors report the first results of a new 6-F symmetrically designed permanent nitinol inferior vena cava (IVC) filter, the Cordis TrapEase, evaluated in a multicenter prospective study with 6-months of follow-up.nnnMATERIALS AND METHODSnA total of 65 patients (29 men, 36 women) who ranged in age from 37 to 96 years (mean age, 68 years) and who were at high risk of pulmonary embolism (PE) were enrolled in 12 centers in Europe and Canada. The study was approved by the institutional review boards at all centers. Study objectives were to evaluate filter effectiveness, filter stability, and caval occlusion. Indications for filter placement were deep vein thrombosis with recurrent thromboembolism and/or free-floating thrombus with contraindication to anticoagulation in 37 patients, and complications in achieving adequate anticoagulation in 28 patients. Follow-up included clinical examination, plain film, Doppler ultrasound, CT scan, and nuclear medicine.nnnRESULTSnThe analysis of the data revealed a technical success of 95.4% (three filter-system related implantations not at the intended site, no events of filter tilting) and a clinical success of 100% at 6 months (no cases of symptomatic PE), the study primary endpoint. There were no cases (0%) of filter migration, insertion site thrombosis, filter fracture, or vessel wall perforation. During the study period, there were two cases of filter thrombosis: one case of early symptomatic thrombosis that was successfully treated in the hospital, and one case of nonsymptomatic filter thrombosis detected at 1-month follow-up, with spontaneous recanalization at 3 months. In the latter patient, some residual thrombus was still detected at 6 months. Of the study population of 65 patients, there were 23 deaths. These deaths were not related to the device or the implantation procedure but to the underlying disease process.nnnCONCLUSIONnThis study demonstrates the new nitinol permanent IVC filter to be a safe and an effective device, with a low overall complication rate, for use in patients with thromboembolic disease at high risk of PE.

Recovery G2 Inferior Vena Cava Filter: Technical Success and Safety of Retrieval

PURPOSEnTo assess the safety and technical success of the retrieval of the Recovery G2 filter when implanted for temporary protection against pulmonary embolism.nnnMATERIALS AND METHODSnThe Recovery G2 inferior vena cava (IVC) filter was placed in 120 consecutive patients between September 2005 and September 2006 in a single center. Patients had deep venous thrombosis (DVT) (n = 63), pulmonary embolism and DVT (n = 55), and high risk for pulmonary embolism without recent thromboembolic disease (n = 2). Indications for filter placement included contraindication to anticoagulation (n = 106), failure of anticoagulation (n = 11), and prophylaxis in addition to anticoagulation (n = 3). In patients eligible for filter removal, the authors measured the mean implantation time, filter retrieval success rate, and retrieval procedure time. In addition, they assessed filter tilting, migration, caval penetration, thrombus within the filter, fracture, and caval injury or stenosis.nnnRESULTSnIn the 51 patients who met the criteria for filter removal, filter tilting (>15 degrees ) was seen in six patients (12%), small thrombi were seen in filters of 15 patients (29%), presumed caval penetration was seen in nine patients (18%), and caudal filter migration was seen in two patients (3.9%). There were no fractures or cephalic migrations. Removal attempts were successful in all 51 patients (100%). The mean implantation time was 53.4 days (range, 7-242 days), and the retrieval procedure time averaged 16.8 minutes (range, 5-60 minutes).nnnCONCLUSIONSnRetrieval of the Recovery G2 filter is safe and can be performed successfully in patients who no longer need IVC filtration.

Relationship between pre-TIPS liver perfusion by the portal vein and the incidence of post-TIPS chronic hepatic encephalopathy

OBJECTIVE:In the present study we evaluated the predictive value of pretransjugular intrahepatic portosystemic shunt (TIPS) portal perfusion as assessed by Doppler ultrasonography for the onset of chronic encephalopathy after TIPS.METHODS:A total of 231 cirrhotic patients were followed-up prospectively after TIPS placement. The pattern of intrahepatic portal flow was assessed before TIPS. Patients were divided into two groups according to Doppler findings. Group 1 comprised patients with prograde portal flow (n = 200), whereas group 2 comprised those with loss of portal perfusion (hepatofugal or back-and-forth flow or portal vein thrombosis; n = 31). The presence of chronic encephalopathy during a median follow-up of 32 months was prospectively recorded. The prognostic value of the following parameters for the onset of chronic recurrent encephalopathy after TIPS was evaluated: age, presence of encephalopathy before TIPS, alcoholism, Pugh score, and loss of portal perfusion before TIPS. The independent prognostic value of each variable was tested with a multiple logistic regression analysis.RESULTS:The two groups were comparable in terms of age, incidence of prior episodes of hepatic encephalopathy, and portacaval gradient before and after the procedure; however, liver failure was more severe in patients in group 2 (Pugh score: 9.2 ± 1.9 vs 10.3 ± 1.7). The 3-yr survival was identical for both groups; 25% of the 200 patients in group 1 developed chronic encephalopathy as compared to 6% of the 31 patients in group 2 (p = 0.03). Multiple logistic regression analysis demonstrated that loss of portal perfusion and age >65 yr were the only independent predictors of the onset of post-TIPS chronic encephalopathy (odds ratios 0.24 and 1.98, respectively).CONCLUSIONS:Cirrhotic patients with loss of portal perfusion before TIPS were protected against post-TIPS chronic hepatic encephalopathy despite a more severe liver dysfunction at baseline. The only other independent predictive factor for the onset of this complication was age.

Effect of the Learning Process on Procedure Times and Radiation Exposure for CT Fluoroscopy-guided Percutaneous Biopsy Procedures

PURPOSEnTo assess if the learning process associated with computed tomography fluoroscopy (CTF) technology influences procedure and fluoroscopy times for percutaneous biopsy procedures.nnnMATERIALS AND METHODSnProspective analysis of the initial 250 consecutive patients who underwent percutaneous biopsy with use of a CT scanner equipped with rapid image reconstruction and fluoroscopic capabilities in a 24-month period. All procedures were performed with both continuous and spot fluoroscopic technique, with typical radiation parameters of 50 mA, 120 kV, and a 10-mm-slice thickness. The procedures were all performed by a single experienced interventional radiologist to limit the variables of physician expertise, interventional materials used, and biopsy approach. The subject group was divided into five equal consecutive groups of 50 patients. In each subgroup, the authors recorded mean lesion size, success, and complication rates, as well as mean procedure and fluoroscopy times.nnnRESULTSnThe five subgroups were similar patient populations as documented by the absence of statistically significant differences when comparing mean lesion size, procedure success, and complication rates (P > .05; ANOVA test). A statistically significant decrease in mean fluoroscopy (groups 1-5: 50.26 vs 45.24 vs 33.86 vs 32.68 vs 25.8 sec/patient) and mean procedure times (groups 1-5: 30.08 vs 27.9 vs 26.34 vs 25.6 vs 21.6 min/patient) was recorded between the patient subgroups (P < .0001; ANOVA test).nnnCONCLUSIONnThe learning process associated with CTF technology impacts procedure parameters by decreasing both mean procedure and fluoroscopy times, thereby increasing patient turnover and decreasing radiation exposure to the patient and the operator.

Percutaneous embolization of iatrogenic arterial kidney injuries: safety, efficacy, and impact on blood pressure and renal function.

PURPOSEnTo evaluate the efficacy and safety of percutaneous renal artery embolization (RAE) of iatrogenic vascular kidney injuries and the effects of RAE on renal function and arterial blood pressure (BP).nnnMATERIALS AND METHODSnOver a 12-year period, 50 consecutive patients with severe hemorrhage after iatrogenic arterial kidney injuries underwent RAE. Technical success was defined as occlusion of the bleeding site, and clinical success was defined as complete bleeding cessation. The effects on renal function and arterial BP were assessed by comparing the estimated glomerular filtration rate (eGFR), renal function stage (National Kidney Foundation scale), systolic BP, and BP stage (European Society of Hypertension classification) before and after RAE.nnnRESULTSnRAE was technically successful in 49 patients (98%). Two patients were lost to follow-up after RAE. Clinical success was obtained in 40 (83%), 45 (94%), and 47 patients (98%), respectively, at 24, 48, and 96 hours after RAE. Three patients (6%) had minor complications, and one patient (2%) died within 30 days after RAE. Follow-up renal function data (mean, 4 mo) were available for 33 patients (66%). No statistically significant differences in eGFR (P = .186) or renal function stage (P = .183) were apparent after RAE. Follow-up BP data (mean, 3 mo) were available for 28 patients (56%). There were no significant differences in systolic BP (P = .233) or BP stage (P = .745) after RAE.nnnCONCLUSIONSnEmbolization of iatrogenic renal artery injuries is safe and associated with high technical and clinical success rates. It is not associated with a significant worsening of renal function or increase in BP.

Umbilical hemorrhage from a cutaneous varix treated by transjugular intrahepatic portosystemic shunt (TIPS)

1. Dumontier I, Roseau G, Palazzo L, et al. Endoscopic ultrasonography in rectal linitis plastica. Gastrointest Endosc 1997; 46:532–6. 2. Libshitz HI, Lindell MM, Dodd GD. Metastases to the hollow viscera. Radiol Clin North Am 1982;20:487–99. 3. Taal BG, Den Hartog Jager FCA, Steinmetz R, et al. The spectrum of gastrointestinal metastases of breast carcinoma: I. Stomach. Gastrointest Endosc 1992;38:130–5. 4. Taal BG, Den Hartog Jager FCA, Steinmetz R, et al. The spectrum of gastrointestinal metastases of breast carcinoma: II. The colon and rectum. Gastrointest Endosc 1992;34:136–41.

Pulmonary arteriovenous malformation (PAVM) reperfusion after percutaneous embolization: Sensitivity and specificity of non-enhanced CT

PURPOSEnTo evaluate the sensitivity and specificity of non-enhanced chest CT to detect reperfusion after pulmonary arteriovenous malformation (PAVM) embolization.nnnMATERIALS AND METHODSnThe Institutional Review Board approved this retrospective HIPAA-compliant study and waived the need for patient consent. All consecutive patients who underwent PAVM embolization between January 2000 and April 2011 were included. Complex PAVMs and patients without available pre- and/or post-embolization CT were excluded. PAVM artery, aneurysm and vein diameters were measured on non-enhanced chest CT before and after PAVM embolization. Pulmonary angiography (PA) was the reference standard to assess PAVM reperfusion. Reperfusion detection was analyzed with receiver operating characteristic (ROC) curves according to percentage of diameter reduction cut-off. Inter-observer concordance was ascertained with intra-class correlation coefficients (ICCs).nnnRESULTSnOut of 68 patients with PAVM embolizations, 42 (62%) had 108 PAVMs that met inclusion/exclusion criteria. Areas under the ROC curves for PAVM reperfusion detection were 0.84, 0.87, and 0.78, respectively, for PAVM artery, aneurysm and vein (p>0.05). Sensitivity varied between 51% and 56%, and specificity between 86% and 98% for the <30% diameter reduction cut-off. Sensitivity was between 98% and 100%, and specificity, between 20% and 47% for the <70% diameter reduction cut-off. ICCs for inter-observer concordance were 0.58, 0.88 and 0.68 for percentage reduction of PAVM artery, aneurysm and vein, respectively.nnnCONCLUSIONnPAVM diameter reduction cut-offs of <30% and <70%, to detect PAVM reperfusion on non-enhanced CT reported in the literature, would respectively result in low sensitivity and specificity.

Management of peripheral arterial disease: role of computed tomography angiography and magnetic resonance angiography.

The recent technological developments of CT and MR units enable fast angiographic acquisitions with an improved spatial and temporal resolution. With advanced 3D visualisation, image post-processing and vessel wall-imaging, these technologies are now almost replacing diagnostic angiography that is now mainly indicated in case of suboptimal computed tomography angiography (CTA) or magnetic resonance angiography (MRA) examinations. Catheter angiography is now used to guide endovascular therapy and the planning of endovascular intervention will rely mainly on CTA or MRA examinations. The relative indications of MRA and CTA for the assessment and follow-up of peripheral arterial disease are based on the clinical indication, potential contraindication and the accessibility. We will review in this chapter, the technical requirements to perform adequate CTA and MRA examination, the relative indications of both modalities for the diagnosis and management of peripheral arterial occlusive disease (PAOD) and abdominal and peripheral aneurysm diseases. The main imaging features observed in these patients will be detailed.

LI-RADS for MR Imaging Diagnosis of Hepatocellular Carcinoma: Performance of Major and Ancillary Features

Purpose To evaluate the performance of major features, ancillary features, and categories of Liver Imaging Reporting and Data System (LI-RADS) version 2014 at magnetic resonance (MR) imaging for the diagnosis of hepatocellular carcinoma (HCC). Materials and Methods This retrospective institutional review board-approved study included patients with liver MR imaging and at least one pathologically proved lesion. Between 2004 and 2016, 102 patients (275 observations including 113 HCCs) met inclusion criteria. Two radiologists independently assessed major and ancillary imaging features for each liver observation and assigned a LI-RADS category. Per-lesion estimates of diagnostic performance of major features, ancillary features, and LI-RADS categories were assessed by using generalized estimating equation models. Results Major features (arterial phase hyperenhancement, washout, capsule, and threshold growth) had a sensitivity of 88.5%, 60.6%, 32.9%, and 41.6%, and a specificity of 18.6%, 84.8%, 98.8%, and 83.2% for HCC, respectively. Ancillary features (mild-moderate T2 hyperintensity, restricted diffusion, mosaic architecture, intralesional fat, lesional fat sparing, blood products, and subthreshold growth) had a sensitivity of 62.2%, 54.8%, 9.9%, 30.9%, 23.1%, 2.8%, and 48.3%, and a specificity of 79.4%, 90.6%, 99.4%, 94.2%, 83.1%, 99.3%, and 91.4% for HCC, respectively. The LR-5 or LR-5 V categories had a per-lesion sensitivity of 50.8% and a specificity of 95.8% for HCC, respectively. The LR-4, LR-5, or LR-5 V categories (determined by using major features only vs combination of major and ancillary features) had a per-lesion sensitivity of 75.9% and 87.9% and a per-lesion specificity of 87.5% and 86.2%, respectively. Conclusion The use of ancillary features in combination with major features increases the sensitivity while preserving a high specificity for the diagnosis of HCC.