Patrick Gilbert

Source of Errors and Accuracy of a Two-Dimensional/Three-Dimensional Fusion Road Map for Endovascular Aneurysm Repair of Abdominal Aortic Aneurysm

PURPOSE To evaluate the accuracy and source of errors using a two-dimensional (2D)/three-dimensional (3D) fusion road map for endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm. MATERIALS AND METHODS A rigid 2D/3D road map was tested in 16 patients undergoing EVAR. After 3D/3D manual registration of preoperative multidetector computed tomography (CT) and cone beam CT, abdominal aortic aneurysm outlines were overlaid on live fluoroscopy/digital subtraction angiography (DSA). Patient motion was evaluated using bone landmarks. The misregistration of renal and internal iliac arteries were estimated by 3 readers along head-feet and right-left coordinates (z-axis and x-axis, respectively) before and after bone and DSA corrections centered on the lowest renal artery. Iliac deformation was evaluated by comparing centerlines before and during intervention. A score of clinical added value was estimated as high (z-axis < 3 mm), good (3 mm ≤ z-axis ≤ 5 mm), and low (z-axis > 5 mm). Interobserver reproducibility was calculated by the intraclass correlation coefficient. RESULTS The lowest renal artery misregistration was estimated at x-axis = 10.6 mm ± 11.1 and z-axis = 7.4 mm ± 5.3 before correction and at x-axis = 3.5 mm ± 2.5 and z-axis = 4.6 mm ± 3.7 after bone correction (P = .08), and at 0 after DSA correction (P < .001). After DSA correction, residual misregistration on the contralateral renal artery was estimated at x-axis = 2.4 mm ± 2.0 and z-axis = 2.2 mm ± 2.0. Score of clinical added value was low (n = 11), good (n= 0), and high (n= 5) before correction and low (n = 5), good (n = 4), and high (n = 7) after bone correction. Interobserver intraclass correlation coefficient for misregistration measurements was estimated at 0.99. Patient motion before stent graft delivery was estimated at x-axis = 8 mm ± 5.8 and z-axis = 3.0 mm ± 2.7. The internal iliac artery misregistration measurements were estimated at x-axis = 6.1 mm ± 3.5 and z-axis = 5.6 mm ± 4.0, and iliac centerline deformation was estimated at 38.3 mm ± 15.6. CONCLUSIONS Rigid registration is feasible and fairly accurate. Only a partial reduction of vascular misregistration was observed after bone correction; minimal DSA acquisition is still required.

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

PURPOSE To 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). MATERIALS AND METHODS Over 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. RESULTS RAE 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. CONCLUSIONS Embolization 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.

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

PURPOSE To evaluate the sensitivity and specificity of non-enhanced chest CT to detect reperfusion after pulmonary arteriovenous malformation (PAVM) embolization. MATERIALS AND METHODS The 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). RESULTS Out 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. CONCLUSION PAVM 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.

Cone-beam CT: An Additional Imaging Tool in the Interventional Treatment and Management of Low-flow Vascular Malformations

PURPOSE To evaluate the impact of cone-beam computed tomography (CT) during sclerotherapy of low-flow vascular malformations. MATERIALS AND METHODS Eighty-seven cone-beam CT examinations were acquired during 81 sclerotherapy treatments of low-flow malformations in 48 patients: 81 were performed to evaluate sclerosing agent diffusion and six were performed to evaluate needle or catheter positioning before injection of therapeutic agent. Image quality was rated by two observers. Clinical impact of cone-beam CT in the assessment of therapeutic agent diffusion, needle or catheter positioning, subsequent treatment planning, and complication detection was evaluated. The κ-statistic was used to assess interobserver reliability and proportions, with associated 95% confidence intervals (CIs). RESULTS All cone-beam CT images were successfully acquired. Image quality was rated as excellent or good for the majority of studies, with substantial interobserver reliability (κ = 0.648). Cone-beam CT studies improved assessment of therapeutic agent diffusion in 83% of cases (67 of 81; 95% CI, 75%-91%) for observer 1, who had access to ultrasound, fluoroscopic, and digital subtraction angiographic (DSA) imaging, and in 95% of cases (77 of 81; 95% CI, 90%-100%) for observer 2, who had access to only stored fluoroscopic spot radiographs and DSA images. Cone-beam CT impacted planning of the next treatment session in 49% of cases (40 of 81; 95% CI, 38%-60%). In 7% of cases (six of 81; 95% CI, 1%-13%), complications such as migration of therapeutic agent or compression of upper airways were detected that were not seen with other imaging. CONCLUSIONS Cone-beam CT can be a useful adjunctive imaging tool, providing information to help decision-making during percutaneous sclerotherapy and ongoing management of low-flow vascular malformations.

Adrenal vein sampling in primary aldosteronism: concordance of simultaneous vs sequential sampling

OBJECTIVE Many investigators believe that basal adrenal venous sampling (AVS) should be done simultaneously, whereas others opt for sequential AVS for simplicity and reduced cost. This study aimed to evaluate the concordance of sequential and simultaneous AVS methods. DESIGN AND METHODS Between 1989 and 2015, bilateral simultaneous sets of basal AVS were obtained twice within 5 min, in 188 consecutive patients (59 women and 129 men; mean age: 53.4 years). Selectivity was defined by adrenal-to-peripheral cortisol ratio ≥2, and lateralization was defined as an adrenal aldosterone-to-cortisol ratio ≥2, the contralateral side. Sequential AVS was simulated using right sampling at -5 min (t = -5) and left sampling at 0 min (t = 0). RESULTS There was no significant difference in mean selectivity ratio (P = 0.12 and P = 0.42 for the right and left sides respectively) and in mean lateralization ratio (P = 0.93) between t = -5 and t = 0. Kappa for selectivity between 2 simultaneous AVS was 0.71 (95% CI: 0.60-0.82), whereas it was 0.84 (95% CI: 0.76-0.92) and 0.85 (95% CI: 0.77-0.93) between sequential and simultaneous AVS at respectively -5 min and at 0 min. Kappa for lateralization between 2 simultaneous AVS was 0.84 (95% CI: 0.75-0.93), whereas it was 0.86 (95% CI: 0.78-0.94) and 0.80 (95% CI: 0.71-0.90) between sequential AVS and simultaneous AVS at respectively -5 min at 0 min. CONCLUSIONS Concordance between simultaneous and sequential AVS was not different than that between 2 repeated simultaneous AVS in the same patient. Therefore, a better diagnostic performance is not a good argument to select the AVS method.

New Treatment Approaches to Arteriovenous Malformations

Arteriovenous malformations (AVMs) are high-flow vascular anomalies that have demonstrated a very high recurrence rate after endovascular treatment, surgical treatment, or a combination of both. Surgical treatments have shown good response when they are small and well localized but a poor response when diffuse. A better understanding of the nature of the lesion has led to a better response rate and a safer treatment for these patients. This has been accomplished through a detailed understanding of the angioarchitecture of the lesion, enabling a tailored approach in reaching and targeting the nidus of the AVM with different liquid embolic agents, more specifically ethanol. Flow reduction techniques help in exposing the nidus to sclerosant agents. A clinical classification, the Schobinger classification, will help determine the appropriate time to start or to pursue therapy.

Assessment of Response to Transcatheter Arterial Chemoembolization with Doxorubicin-eluting Microspheres: Tumor Biology and Hepatocellular Carcinoma Recurrence in a 5-year Transplant Cohort

Purpose To assess response to transcatheter arterial chemoembolization (TACE) based on immune markers and tumor biology in patients with hepatocellular carcinoma (HCC) who were bridged to liver transplantation, and to produce an optimized pretransplantation model for posttransplantation recurrence risk. Materials and Methods In this institutional review board-approved HIPAA-compliant retrospective analysis, 93 consecutive patients (73 male, 20 female; mean age, 59.6 years; age range, 23-72 years) underwent TACE with doxorubicin-eluting microspheres (DEB) (hereafter, DEB-TACE) and subsequently underwent transplantation over a 5-year period from July 7, 2011, to May 16, 2016. DEB-TACE response was based on modified Response Evaluation Criteria in Solid Tumors. Imaging responses and posttransplantation recurrence were compared with demographics, liver function, basic immune markers, treatment dose, and tumor morphology. Treatment response and recurrence were analyzed with uni- and multivariate statistics, as well as internal validation and propensity score matching of factors known to affect recurrence to assess independent effects of DEB-TACE response on recurrence. Results Low-grade tumors (grade 0, 1, or 2) demonstrated a favorable long-term treatment response in 87% of patients (complete response, 49%; partial response, 38%; stable disease [SD] or local disease progression [DP], 13%) versus 33% of high-grade tumors (grade 3 or 4) (complete response, 0%; partial response, 33%; SD or DP, 67%) (P < .001). Of the 93 patients who underwent treatment, 82 were followed-up after transplantation (mean duration, 757 days). Recurrence occurred in seven (9%) patients (mean time after transplantation, 635 days). Poor response to DEB-TACE (SD or DP) was present in 86% of cases and accounted for 35% of all patients with SD or DP (P < .001). By using only variables routinely available prior to liver transplantation, a validated model of posttransplantation recurrence risk was produced with a concordance statistic of 0.83. The validated model shows sensitivity of 83.6%, specificity of 82.6%, and negative predictive value of 98.4%, which are pessimistic estimates. Conclusion Response to DEB-TACE is correlated with tumor biology and patients at risk for posttransplantation recurrence, and it may be associated with HCC recurrence after liver transplantation.

Adrenal venous sampling in primary aldosteronism: multinomial regression modeling to detect aldosterone secretion lateralization when right adrenal sampling is missing

Objective: Difficulty to recognize or canulate the right adrenal vein is the most frequent cause of adrenal venous sampling (AVS) failure. We aimed to assess multinomial regression modeling (MRM) of peripheral and left adrenal vein samplings to detect lateralization of aldosterone secretion when the right AVS is missing. Methods: Simultaneous bilateral AVS samplings were performed before (basal) and after intravenous cosyntropin injection in 188 consecutive patients between December 1989 and September 2015. Different reference standards for lateralization of aldosterone secretion were defined for basal and for postcosyntropin AVS and according to lateralization index cutoffs at least 2 and at least 4. MRMs were built to detect lateralization of aldosterone secretion according to these reference standards using only peripheral and left adrenal veins samplings (without the right AVS). Detection accuracy was assessed by the area under the receiver operating characteristic (AUROC) curves and detection sensitivities were reported for specificity at least 95%. Results: For basal AVS with lateralization index at least 2, AUROC were respectively 0.931 [95% confidence interval (CI) 0.894–0.968] and 0.922 (95% CI 0.882–0.962) for right and left lateralization of aldosterone secretion detection and MRM could detect respectively 65.5 and 62.7% of the right and left lateralization of aldosterone secretion. For AVS after cosyntropin with lateralization index at least 4, AUROC were respectively 0.964 (95% CI: 0.940–0.987) and 0.955 (95% CI: 0.927–0.983) for right and left lateralization of aldosterone secretion, and MRM could detect respectively 77.2 and 72.9% of the right and left lateralization of aldosterone secretion. Conclusion: MRM can detect lateralization of aldosterone secretion without the right AVS in most patients and could eliminate the need for repeat AVS when right adrenal vein canulation is nonselective or impossible.

Arteriovenous Fistula Embolization in Suspected Parauterine Choriocarcinoma

This is a case of choriocarcinoma that did not regress after chemotherapy treatment. A 30-year-old female patient (gravida 2, para 2), presented to our ER with stroke and persistent mild pelvic pain 2 months after a Caesarean section. Computed tomography (CT) revealed an ischemic left hemicerebellar region and a hypervascular mass in the pelvic region. This mass was not present on routine fetal ultrasound during pregnancy. The lesion was treated by chemotherapy after closure of a foramen ovale and insertion of an inferior vena cava (IVC) filter. After that, 2 courses of EMACO (Etoposide, Methotrexate, Actinomycin D, Cyclophosphamide, and Vincristine) chemotherapy regimen were given. Posttreatment CT showed the hypervascular mass without any changes. Arteriography showed the arteriovenous fistulae that were embolized successfully with plugs, coils, and glue. Embolization was considered due to the risk of acute hemorrhagic life-threatening complications. Eight chemotherapy courses were added after embolization. Treatment by endovascular approach and reduction of the hypervascular mass can be a valuable adjunct to chemotherapy treatment of choriocarcinoma.