Preemptive embolization of abdominal aortic aneurysm sac side branch arteries promotes early sac shrinkage after endovascular aneurysm repair1.

OBJECTIVES: The association between the occlusion rate of the side branch arteries branching from the abdominal aortic aneurysm sac and aneurysm sac shrinkage is unclear. We aimed to evaluate the efficacy of preemptive embolization of multiple side branch arteries branching from the abdominal aortic aneurysm sac in early aneurysm sac shrinkage after endovascular aneurysm repair. METHODS: Patients undergoing endovascular aneurysm repair of abdominal aortic aneurysms, with or without preemptive embolization of multiple side branch arteries, including the inferior mesenteric artery and lumbar arteries, between January 2016 and August 2021, were retrospectively evaluated. Preemptive embolization was introduced at our institution in January 2018 and has been performed in all patients who undergo endovascular aneurysm repair since then. We compared occlusion rates of the side branch arteries, frequency of type 2 endoleaks, changes in aneurysm sac size, percentage of aneurysm sac size decrease, and frequency of reduction in the aneurysm sac diameter by >5 mm. RESULTS: The study included 43 patients in the embolization group and 20 in the non-embolization group. Preemptive embolization was successfully performed without any ischemic complications. The total occlusion rate of side branch arteries was significantly higher in the embolization group than in the non-embolization group (70.2% vs. 29.3%, P<0.05). At 24 months of follow-up, the type 2 endoleak frequency was significantly lower in the embolization group than in the non-embolization group (6.9% vs. 31.6%, P<0.05). The frequency of reduction in the aneurysm sac diameter by >5 mm was significantly higher in the embolization group than in the non-embolization group at 24 months (62.1% vs. 31.6% P<0.05). The optimal cutoff value for the total occlusion rate of the side branch arteries to achieve reduction in the aneurysm sac diameter by >5 mm at 24 months, after endovascular aneurysm repair, was 66.7% in all patients (area under the curve=0.634; sensitivity=62.5%; specificity=70.8%). These findings suggest that occluding 66.7% or more of the side branch arteries may result in early aneurysmal shrinkage. CONCLUSION: Preemptive embolization of multiple side branch arteries, branching from the abdominal aortic aneurysm sac, may contribute to early aneurysm sac shrinkage; this may serve as a marker for fewer late complications after endovascular aneurysm repair.

Impact of System-F in Delivering Vascular Plugs for Aortic Side Branch Embolization During Endovascular Aneurysm Repair.

PURPOSE: This study aimed to illustrate the utility of our original system to deliver vascular plugs into aortic side branches during endovascular aneurysm repair (EVAR). TECHNIQUE: Our device, which we named "System-F," consists of a 14 Fr sheath, a 12 Fr long sheath with a side hole, a stiff guidewire as a shaft, and a parallelly-inserted delivery catheter navigated through the side hole into the aneurysm sac. Vertical motion and horizontal rotation of the side hole allow multidimensional movement of the delivery catheter within the aneurysm. This system was applied in 7 cases undergoing EVAR; 4 inferior mesenteric arteries and 14 lumbar arteries were embolized using vascular plugs. Type II endoleak (T2EL) was not observed in the follow-up survey of any case. Conclusion: The applicability of System-F for vascular plug placement in the side branches of abdominal aortic aneurysms has the potential to achieve high delivery capability and be widely applied for the prevention of T2EL. CLINICAL IMPACT: System-F has potential to change the strategies of pre-EVAR embolization.

Comparison of Slow-Infusion Magnetic Resonance Angiography with Sequential K-Space Filling and Computed Tomography Angiography to Detect the Adamkiewicz Artery.

BACKGROUND: Radiographic detection of the Adamkiewicz artery (AKA) before aortic surgery helps to avoid spinal cord ischemia (SCI). We applied magnetic resonance angiography (MRA) using gadolinium enhancement (Gd-MRA) by means of the slow-infusion method with sequential k-space filling and compared AKA detectability with that of computed tomography angiography (CTA). METHODS: A total of 63 patients with thoracic or thoracoabdominal aortic disease (30 with aortic dissection [AD] and 33 with aortic aneurysm) who underwent both CTA and Gd-MRA to detect AKA were evaluated. The detectability of the AKA using Gd-MRA and CTA were compared among all patients and subgroups based on anatomical features. RESULTS: The detection rates of the AKAs using Gd-MRA and CTA were higher in all 63 patients (92.1% vs. 71.4%, P = 0.003). In AD cases, the detection rates using Gd-MRA and CTA were higher in all 30 patients (93.3% vs. 66.7%, P = 0.01) as well as in 7 patients whose AKA originated from false lumens (100% vs. 0%). In aneurysm cases, the detection rates using Gd-MRA and CTA were higher in 22 patients whose AKA originated from the nonaneurysmal parts (100% vs. 81.8%, P = 0.03). In clinical, SCI was observed in 1.8% of cases after open or endovascular repair. CONCLUSIONS: Despite the longer examination time and more complicated imaging techniques compared to those of CTA, the high spatial resolution of slow-infusion MRA may be preferable for detecting AKA before performing various thoracic and thoracoabdominal aortic surgeries.

Localization of Late Gadolinium Enhancement and Its Association with Ventricular Tachycardia in Patients with Cardiac Sarcoidosis.

Sustained ventricular tachycardia (sVT), leading to sudden cardiac death, is one of the common manifestations in cardiac sarcoidosis (CS). Although late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) has been reported to be associated with sVT, the relationships of its localization to sVT have not been fully evaluated.To evaluate the localization of LGE and its relationships to sVT in patients with CS, we reviewed medical record of consecutive 31 patients with CS who underwent CMR. The localization of LGE was divided into four categories: Left ventricular (LV) septum, LV free wall, right ventricular (RV) septum, and RV free wall. We investigated the association of sVT with localization of LGE and other parameters including serum biomarkers LV ejection fraction on echocardiography and Fluorine-18-fluorodeoxyglucose (FDG) accumulation on positron emission tomography (PET) -CT.Of the studied population, 8 patients (25.8%) were known to present with sVT among 31 CS patients. LGE was observed in the RV free wall in 6 patients with sVT, whereas it was in 5 patients without sVT (75.0% versus 21.7%, P = 0.022). Univariate analysis showed that only LGE in the RV free wall was associated with sVT (odds ratio [OR]: 10.80; 95% confidence interval [CI]: 1.64-70.93, P = 0.013).LGE in the RV free wall was associated with sVT in patients with CS.

Computed Tomography Attenuation Values of the High-Attenuating Crescent Sign Can Discriminate Between Rupture, Impending Rupture, and Non-Rupture of Aortic Aneurysms.

BACKGROUND: Although the high-attenuating crescent (HAC) sign can indicate aortic aneurysm (AA) impending rupture, the relation of its computed tomography (CT) value to the aneurysmal status remains unclear. This study compared the HAC sign CT-attenuation values among rupture, impending rupture, and non-rupture AA cases.Methods and Results:This included 76 patients (mean age: 77.0 years) diagnosed with HAC sign-associated AA between January 2005 and July 2015. The CT-attenuation values of the HAC sign (H) and aortic lumen (A) using region-of-interest methodology were measured and the H/A ratio was calculated. The study classified patients into the rupture group (R-G, n=36), impending rupture group (IR-G, n=16), and non-rupture group (NR-G, n=24); the H and the H/A ratio were compared among them. Additionally, the H and the H/A ratio cut-offs between the IR-G and NR-G groups were evaluated. The H and the H/A ratio were significantly higher in the R-G and IR-G than in the NR-G (both P<0.001); the H/A ratio was significantly higher in the R-G than in the IR-G (P=0.038). The optimal cut-off for H between the IR-G and NR-G was 50.3 Hounsfield units (area under the curve [AUC]=0.875; sensitivity=87.5%; specificity=87.5%), and that for the H/A ratio was 1.3 (AUC=0.909; sensitivity=91.7%; specificity=87.5%). CONCLUSIONS: Among patients with AA, the H and the H/A ratio were significantly higher in cases of rupture and impending rupture than in those of non-rupture.

A Comparison of Outcomes Based on Vessel Type (Native Artery vs. Bypass Graft) and Artery Location (Below-Knee Artery vs. Non-Below-Knee Artery) Using a Combination of Multiple Endovascular Techniques for Acute Lower Limb Ischemia.

BACKGROUND: To evaluate outcomes of endovascular treatment (EVT) using a combination of multiple endovascular techniques for acute lower limb ischemia (ALLI) and to compare outcomes based on vessel type and artery location. METHODS: A total of 95 consecutive patients with ALLI (mean age, 72.0 years; 65 males; 104 lower limbs) who received emergency EVT using a combination of multiple endovascular techniques including thrombolysis, aspiration thrombectomy, stenting, and balloon angioplasty with or without surgical thromboembolectomy, between January 2005 and December 2017 were included. Vessel type was classified into native artery occlusion (native occlusion) and bypass graft occlusion (graft occlusion), including prosthetic and vein graft. Additionally, native arteries were categorized into below-knee occlusion and non-below-knee occlusion. Technical success, perioperative death (POD), ALLI-related death, amputation, amputation-free survival (AFS), and complications were compared according to vessel type (native occlusion vs. graft occlusion) and artery location (below-knee occlusion vs. non-below-knee occlusion). RESULTS: Of all patients with ALLI, 16.8% underwent a single endovascular technique, whereas 83.2% underwent a combination of multiple endovascular techniques. The technicalsuccess, POD, and ALLI-related death rates in the total number of patients were 94.7%, 11.6%, and 4.2%, respectively. A total of 67 patients (75 limbs) and 28 patients (29 limbs) were classified as having native occlusion and graft occlusion (prosthetic, 24 limbs; vein, 5 limbs), respectively. No significant differences in technical success (native occlusion: 92.5% vs. graft occlusion: 100%), POD (14.9% vs. 3.6%), and ALLI-related death (6.0% vs. 0%) were noted between native occlusion and graft occlusion. However, the 30-day AFS rate of native occlusion was significantly lower than that of graft occlusion (75.2% vs. 96.3%, P=0.01). The amputation rate (P=0.03) and AFS rate (P=0.03) of below-knee occlusion were significantly worse for below-knee occlusion patients than for non-below-knee occlusion patients. CONCLUSIONS: EVT using multiple endovascular techniques for ALLI is effective and safe. A combination of multiple endovascular techniques is crucial for successful treatment. However, native occlusion may have a lower AFS rate than graft occlusion, and below-knee occlusion may have a higher risk of amputation than non-below-knee occlusion.

Multiparametric flow analysis using four-dimensional flow magnetic resonance imaging can detect cerebral hemodynamic impairment in patients with internal carotid artery stenosis.

PURPOSE: MRI-based risk stratification should be established to identify patients with internal carotid artery stenosis (ICS) who require further PET or SPECT evaluation. This study assessed whether multiparametric flow analysis using time-resolved 3D phase-contrast (4D flow) MRI can detect cerebral hemodynamic impairment in patients with ICS. METHODS: This retrospective study analyzed 26 consecutive patients with unilateral ICS (21 men; mean age, 71 years) who underwent 4D flow MRI and acetazolamide-stress brain perfusion SPECT. Collateral flow via the Willis ring was visually evaluated. Temporal mean flow volume rate (Net), pulsatile flow volume (ΔV), and pulsatility index (PI) at the middle cerebral artery were measured. Cerebral vascular reserve (CVR) was calculated from the SPECT dataset. Patients were assigned to the misery perfusion group if the CVR was < 10% and to the nonmisery perfusion group if the CVR was ≥ 10%. Parameters showing a significant difference in both groups were statistically evaluated. RESULTS: Affected side ΔV, ratio of affected to contralateral side Net (rNet), and ratio of affected to contralateral side ΔV were significantly correlated to CVR (p = 0.030, p = 0.010, p = 0.015, respectively). Absence of retrograde flow at the posterior communicating artery was observed in the misery perfusion group (p = 0.020). Combined cut-off values of the affected side ΔV (0.18 ml) and rNet (0.64) showed a sensitivity and specificity of 100% and 77.8%, respectively. CONCLUSION: Multiparametric flow analysis using 4D flow MRI can detect misery perfusion by comprehensively assessing blood flow data, including blood flow volume, pulsation, and collateral flow.

"Squid-Capture" Modified In Situ Stent-Graft Fenestration Technique for Recurrent Abdominal Aortic Occlusive Disease after Collapse of Balloon-Expandable Stent.

We present a case of an 85-year-old woman with bilateral limb-threatening ischemia caused by acute-on-chronic occlusion of the infrarenal aorta. The patient once underwent endovascular recanalization using nitinol and stainless-steel bare-metal stent implantation; however, the stainless-steel stent collapsed 3 months later. In the second endovascular therapy, "Squid-Capture" modified in situ stent-graft fenestration technique followed by stent-in-stent implantation with stent graft and bare-metal stent was successfully applied, and it can be regarded as a promising treatment option for the repair of abdominal aortic occlusive disease in some limited anatomical conditions.

An Extremely Rare Complication: Abdominal Aortic Aneurysm Rupture Caused by Migration of a Zenith Main Body Years After Repair of the Suprarenal Stent Separation.

PURPOSE: To report an unusual case of an abdominal aortic aneurysm (AAA) rupture caused by migration of a Zenith stent-graft main body years after its separation from the suprarenal stent. CASE REPORT: A 72-year-old man underwent endovascular aneurysm repair with a Zenith stent-graft for an infrarenal AAA in year 2000. At that time, a femorofemoral bypass was performed because the left external iliac and common femoral arteries were dissected during treatment. In 2013, follow-up computed tomography (CT) showed disconnection of the uncovered proximal stent, which led to a type Ia endoleak. An additional Zenith main body and Large Palmaz XL balloon-expandable stent were deployed; the endoleak disappeared. In 2016, the patient had abdominal pain, and emergency CT showed AAA rupture caused by migration of the first main body deployed in 2000 under the distal edge of the contralateral (left) leg of the additional main body from 2013, which led to a type IIIa endoleak between the 2 main bodies. A converter and iliac legs were deployed to successfully seal the type IIIa endoleak. The patient remains well 18 months after the second repair; CT scans document stable stent-grafts and no endoleak. CONCLUSION: Physicians should be aware of the potential risk for AAA rupture caused by late main body migration after treatment for suprarenal stent separation from a Zenith stent-graft.

Haemodynamic changes in hepatocellular carcinoma and liver parenchyma under balloon occlusion of the hepatic artery.

OBJECTIVES: To investigate haemodynamic changes in hepatocellular carcinoma (HCC) and liver under hepatic artery occlusion. METHODS: Thirty-eight HCC nodules in 25 patients were included. Computed tomography (CT) during hepatic arteriography (CTHA) with and without balloon occlusion of the hepatic artery was performed. CT attenuation and enhancement volume of HCC and liver with and without balloon occlusion were measured on CTHA. Influence of balloon position (segmental or subsegmental branch) was evaluated based on differences in HCC-to-liver attenuation ratio (H/L ratio) and enhancement volume of HCC and liver. RESULTS: In the segmental group (n = 20), H/L ratio and enhancement volume of HCC and liver were significantly lower with balloon occlusion than without balloon occlusion. However, in the subsegmental group (n = 18), H/L ratio was significantly higher and liver enhancement volume was significantly lower with balloon occlusion; HCC enhancement volume was similar with and without balloon occlusion. Rate of change in H/L ratio and enhancement volume of HCC and liver were lower in the segmental group than in the subsegmental group. There were significantly more perfusion defects in HCC in the segmental group. CONCLUSIONS: Hepatic artery occlusion causes haemodynamic changes in HCC and liver, especially with segmental occlusion. KEY POINTS: • Hepatic artery occlusion causes haemodynamic changes in hepatocellular carcinoma and liver. • Segmental occlusion decreased rate of change in hepatocellular carcinoma-to-liver attenuation ratio. • Subsegmental occlusion increased rate of change in hepatocellular carcinoma-to-liver attenuation ratio. • Hepatic artery occlusion decreased enhancement volume of hepatocellular carcinoma and liver. • Hepatic artery occlusion causes perfusion defects in hepatocellular carcinoma.

The high matrix acquisition technique for imaging of atherosclerotic plaque inflammation in fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography with time-of-flight: Phantom study.

BACKGROUND: Motion artifact and partial volume effect caused underestimation of coronary plaque inflammation. This study evaluated the high matrix acquisition technique using time-of-flight (TOF) positron emission tomography/computed tomography for imaging of atherosclerotic plaque inflammation with fluorine-18 fluorodeoxyglucose in small and moving phantoms. METHODS AND RESULTS: All images were reconstructed using a conventional algorithm without TOF (4 × 4 × 4 mm3 voxel size) and a high matrix algorithm with TOF (2 × 2 × 2 mm3 voxel size). Microsphere phantoms of 10, 7.9, 6.2, 5.0, and 4.0 mm diameters were acquired in 3-dimensional list-mode for 30 minutes. A heart phantom mimicking cardiac motion consisted of a hot spot simulating a plaque (φ 4 mm, φ 2 mm) on the outside of the left ventricle. In the microsphere and heart phantom study, visual discrimination, maximum activity, and target-to-background ratio using the high matrix algorithm with TOF were better than those using the conventional algorithm without TOF. CONCLUSION: The high matrix algorithm with TOF improves detection of small targets in phantoms.

The reproducibility of time-of-flight PET and conventional PET for the quantification of myocardial blood flow and coronary flow reserve with (13)N-ammonia.

BACKGROUND: This study aimed to validate the reproducibility of quantitative analysis using time-of-flight (TOF) and conventional PET with (13)N-ammonia ((13)N-NH3). METHODS AND RESULTS: Phantom images were reconstructed with and without TOF, and recovery coefficients (RCs) and the percent contrast of each sphere over the percent background variability were assessed. In the clinical study, 21 subjects underwent dynamic (13)N-NH3 PET scanning under stress and rest conditions. The dynamic acquisition images and intra- and inter-observer reproducibility of myocardial blood flow (MBF) and coronary flow reserve (CFR) were compared between reconstructions (with and without TOF). In the phantom study, RCs and the percent contrast of each sphere over the percent background variability was improved with TOF. In the clinical study, the noise of blood pool and myocardial images with TOF was less than that without TOF. Territorial and global intra- and inter-observer reproducibility of MBF and CFR values was excellent. Although segmental intra- and inter-observer reproducibility was excellent, there were larger variations in apex and the segment near the right ventricle (RV) without TOF. These variations became inconspicuous with TOF. CONCLUSION: Visual image quality, RCs, and percent contrast over percent background variability with TOF were better than that without TOF. Excellent correlations and good agreements in quantitative values were observed. TOF improved the variation of segmental values.

4D flow MRI assessment of extracranial-intracranial bypass: qualitative and quantitative evaluation of the hemodynamics.

INTRODUCTION: Our aim was to assess the feasibility of using time-resolved 3D phase-contrast (4D flow) MRI to characterize extracranial-intracranial (EC-IC) bypass. METHODS: We enrolled 32 patients who underwent EC-IC bypass (15 men, 17 women; mean age 66.4 years). In all, 16 underwent radial artery graft (RAG) bypass and 16 underwent superficial temporal artery (STA) bypass. 4D flow MRI, time-of-flight (TOF) magnetic resonance angiography (MRA), and computed tomography angiography (CTA) were performed. Bypass patency, flow direction, and blood flow volume (BFV) of each artery were determined by 4D flow MRI. Arterial diameters were measured by TOF-MRA and CTA. We compared RAG and STA bypasses by evaluating the flow direction and BFV of each artery. We evaluated the correlation between arterial diameters (measured by CTA or MRA) and the BFV and the detectability of flow direction (measured by 4D flow MRI) of each artery. RESULTS: 4D flow MRI confirmed the patency of each bypass artery. Flow direction of the M1 segment of the middle cerebral artery and BFV in the bypass artery differed between RAG and STA groups (p < 0.01). BFV in the bypass slightly correlated with the diameters on CTA (p < 0.05, R (2) = 0.287). Of the 29 arteries in the circle of Willis, nine were not depicted on 4D flow MRI. Cutoff values for arterial diameters on CTA and TOF-MRA for detecting the artery on 4D flow MRI were 2.4 and 1.8 mm, respectively. CONCLUSION: 4D flow MRI provided unique information for characterizing EC-IC bypasses, although this detectability is limited when addressing small arteries with slow flow.

Minimizing Systemic Leakage of Cisplatin during Percutaneous Isolated Pancreas Perfusion Chemotherapy: A Pilot Study.

PURPOSE: To evaluate the feasibility of percutaneous isolated pancreas perfusion (PIPP) by using a pig model. MATERIALS AND METHODS: All experiments were approved by the institutional Animal Experiment Ethics Committee. Fifteen pigs were assigned to five groups, and PIPP was performed. Angiographic and dye injection studies were performed to confirm the patency of the PIPP system (group 1). Blood that contained cisplatin (1.5 mg per kilogram of body weight) in an extracorporeal circuit was circulated through the pancreas at three infusion rates (40, 60, and 80 mL/min) to determine the optimal infusion rate in terms of safety and pharmacologic effectiveness (groups 2, 3, and 4, respectively). Chronological laboratory data and histologic findings were assessed in group 5, which received the optimal infusion rate. Maximum platinum concentration (Cmax) and area under the platinum concentration-time curve were compared by using the Kruskal-Wallis and Mann-Whitney U tests. RESULTS: Angiography and dye injection confirmed the patency of the PIPP system. Histopathologic examinations showed no abnormalities in the pancreas or other organs at a 40 mL/min infusion rate of cisplatin. However, edematous changes in the pancreas were observed at higher infusion rates. The pharmacologic effectiveness did not differ significantly among groups; therefore, the optimal infusion rate of 40 mL/min was selected. The median pancreatic-to-systemic exposure ratios were 71.8 for Cmax and 54.8 for the area under the curve. All laboratory data remained normal or returned to pretreatment levels within 1 week. CONCLUSION: PIPP at a 40 mL/min infusion rate appears to be safe and feasible for perfusion of the pancreas.

Retrograde-outflow percutaneous isolated hepatic perfusion using cisplatin: A pilot study on pharmacokinetics and feasibility.

OBJECTIVES: This study aimed to evaluate the feasibility and underlying pharmacokinetics of the retrograde-outflow technique for percutaneous isolated hepatic perfusion (PIHP). METHODS: Retrograde-outflow PIHP was performed in 12 male pigs (weight, 37-44 kg) by redirecting hepatic outflow through the portal vein. Blood with cisplatin (2.5 mg/kg) in an extracorporeal circuit was circulated through the liver under isolation using rotary pumps with balloon catheters. Hepatic angiographic examinations were conducted during perfusion, and histopathological examinations of the organs were conducted after perfusion. The maximum platinum concentration (C max), area under the concentration-time curve (AUC), and chronologic laboratory data were measured. RESULTS: Retrograde-outflow isolated hepatic angiography confirmed that contrast media flowed into the portal veins in all 12 pigs. The hepatic veins and inferior vena cava were not opacified. Hepatic C max (86.3 mg/l) was 39-fold greater than systemic C max (2.2 mg/l), and hepatic AUC (1330.8 min · mg/l) was 30-fold greater than systemic AUC (44.6 min · mg/l). Histopathological examinations revealed no ischaemic changes or other abnormalities in the liver, duodenum, small intestine, or colon. Within 1 week of the procedure, chronologic laboratory data (n = 3) normalized or returned to pre-therapy levels. CONCLUSIONS: The retrograde-outflow technique appears to enable safe and feasible PIHP therapy. KEY POINTS: • The portal vein acted as an outflow tract under retrograde-outflow PIHP. • Plasma hepatic-to-systemic exposure ratio was 39.2 for the maximum platinum concentration. • Plasma hepatic-to-systemic exposure ratio was 29.8 for the AUC. • The retrograde-outflow technique appears to enable safe and feasible PIHP.

Impact of time-of-flight on qualitative and quantitative analyses of myocardial perfusion PET studies using (13)N-ammonia.

BACKGROUND: The impact of time-of-flight (TOF) in myocardial perfusion (13)N-ammonia positron emission tomography (PET) is unclear. METHODS AND RESULTS: Twenty consecutive subjects underwent rest and adenosine stress (13)N-ammonia myocardial perfusion PET. Two sets of images were reconstructed using TOF-ordered subset expectation maximization (TOF-OSEM) and 3-dimensional row-action maximum likelihood algorithm (3D-RAMLA). Qualitative and quantitative analyses from the TOF-OSEM and 3D-RAMLA reconstructions were compared. Count profile curves revealed that TOF relatively increased the uptake of (13)N-ammonia at the lateral walls, and apical thinning was emphasized on the TOF images. Both segmental rest and stress myocardial blood flow (MBF) values were higher with TOF-OSEM use than with 3D-RAMLA use (rest MBF: 0.955 ± 0.201 vs 0.836 ± 0.185, P < .001; stress MBF: 2.149 ± 0.697 vs 2.058 ± 0.721, P < .001). The differentiation of MBF between reconstructions was more enhanced under rest conditions. Thus, segmental myocardial flow reserve (MFR) observed using TOF-OSEM reconstruction was lower than that observed using 3D-RAMLA (2.25 ± 0.57 vs 2.46 ± 0.75, P < .001). No remarkable differences were observed between segmental and territorial results. CONCLUSIONS: TOF increased lateral wall counts and emphasized apical thinning. Quantitatively, TOF reconstruction showed increased MBF, especially under relatively low perfusion conditions.

Interpretative variability and its impact on the prognostic value of myocardial fatty acid imaging in asymptomatic hemodialysis patients in a multicenter trial in Japan.

BACKGROUND: The severity of impaired fatty acid utilization in the myocardium can predict cardiac death in asymptomatic patients on hemodialysis. However, interpretive variability and its impact on the prognostic value of myocardial fatty acid imaging are unknown. METHODS AND RESULTS: A total of 677 patients who received hemodialysis for ≥ 20 years and had one or more cardiovascular risk factors underwent (123)I-labeled ß-methyl iodophenyl-pentadecanoic acid (BMIPP) single-photon emission computed tomography (SPECT) at 48 hospitals across Japan. SPECT images were interpreted by experts at the nuclear core laboratory and by readers with varying skill levels at clinical centers, based on the standard 17-segment model and 5-point scoring systems, independently. The κ values only reached fair agreement both for overall impression (κ=0.298, normal vs. abnormal) and for categorical impression (κ=0.244, normal vs. mildly abnormal vs. severely abnormal). The normalcy rate was lower in readers at the clinical centers (60.9%) than in experts (69.9%). In contrast to the results assessed by experts, a Kaplan-Meier analysis based on the interpretation by readers at the clinical centers failed to distinguish the risk of events in patients with normal scans from that of patients with mildly abnormal scans. CONCLUSIONS: Considerable variability and its impact on prognostic value were observed in the visual interpretation of BMIPP SPECT images between experts and readers at the clinical centers.

Contribution of extrahepatic collaterals to liver parenchymal circulation after proper hepatic artery embolization.

BACKGROUND AND AIM: To retrospectively evaluate proper hepatic artery embolization, with respect to the development of extrahepatic collaterals. METHODS: Proper hepatic artery embolization was performed in 18 patients with hemorrhagic arterial lesions in the hepatic hilum. Post-procedural development of extrahepatic collaterals was evaluated by computed tomography or angiography. Embolization data and liver function tests were assessed. The correlation of outcomes with portal venous stenosis, hepatic failure prior to embolization, elevation of prothrombin time, and insufficient collateral development were analyzed. RESULTS: Postoperative bleeding occurred in 17/18 patients, and one was treated for an idiopathic aneurysm of the proper hepatic artery; all treatments achieved technical success. Extrahepatic collaterals were confirmed in 13 patients. Elevations of liver function test values were transient and returned to baseline within 14 days in patients with collateral development (n = 13), but were unimproved in patients without collaterals (n = 5) (P < 0.001). Portal venous stenosis; prior hepatic failure; unrecovered, elevation of prothrombin time; and insufficient collateral development were significantly correlated with poor outcomes (P < 0.05, respectively). CONCLUSIONS: Proper hepatic artery embolization is effective for hemostasis, and extrahepatic collateral development is expected. Therefore, this is a safe treatment without prolonged hepatic ischemic damage, especially in patients without severe portal venous stenosis or prior hepatic failure.

Negative-balance isolated pelvic perfusion in patients with incurable symptomatic rectal cancer: results and drug dose correlation to adverse events.

BACKGROUND: Drug leakage and lack of a drug-removal system have prevented clinical application of isolated pelvic perfusion (IPP). These barriers were overcome with negative-balance IPP (NIPP) in experimental pig models. Here, a phase 1 clinical study of NIPP was performed in patients with incurable symptomatic rectal cancer. PURPOSE: To establish a safe regimen of high-dose regional chemotherapy with NIPP using cisplatin in patients with incurable rectal cancer. MATERIAL AND METHODS: Between June 2004 and January 2007, NIPP therapy was performed for 23 patients (11 women, 12 men; mean age, 58 years). NIPP was routinely performed twice over a 4-week interval. Dose-limiting toxicities (DLTs) were defined using a 5 + 3 design, and cisplatin doses were escalated from 170 mg/m(2), with a fixed 5-fluorouracil dose of 1000 mg/m(2). The grade of adverse events (AEs) at the first and second sessions of NIPP therapy, pharmacokinetics, and antitumor response were evaluated. RESULTS: No DLTs were observed during the first session of NIPP. However, at the second session, two patients experienced the DLT of neuropathy after administration of 200 mg/m(2) cisplatin. Therefore, 190 mg/m(2) cisplatin was indicated as the maximum tolerated dose (MTD). The plasma pelvic-to-systemic exposure ratio was 18.4 based on the maximum concentration and 19.0 based on the concentration-time curve. Solid tumor responses included complete response in two patients, partial response in five patients, stable disease in 15 patients, and progressive disease in one patient. CONCLUSION: NIPP may offer the safe delivery of high-dose regional chemotherapy (MTD of 190 mg/m(2) cisplatin) with negligible AEs and effective control of tumor growth in patients with incurable rectal cancer.