Increase in hepatic arterial blood flow after transjugular intrahepatic portosystemic shunt creation and its potential predictive value of postprocedural encephalopathy and mortality.

PURPOSE: To determine (i) whether there is a significant increase in hepatic artery blood flow (HABF) after transjugular intrahepatic portosystemic shunt (TIPS) creation and (ii) whether the extent of incremental increase in HABF is predictive of clinical outcome after TIPS creation. MATERIALS AND METHODS: Prospective, nonrandomized, nonblinded duplex Doppler ultrasound (US) examinations were performed on 24 consecutive patients (19 men; Child Class A/B/C: 4/12/8, respectively) with a mean age of 52.8 years who were referred for TIPS creation for variceal bleeding. Peak hepatic artery velocity and vessel dimensions were used to calculate the hepatic arterial blood flow (HABF) before and after TIPS creation. Patients were clinically followed in the gastrohepatology clinic and TIPS US surveillance was performed at 1 and 3 months to assess shunt function. The extent of incremental increase in HABF was analyzed as a predictor of post-TIPS encephalopathy and/or death. RESULTS: The technical success rate of TIPS creation was 100%. The shunt diameters were either 10 mm (n = 11) or 12 mm (n = 13). TIPS resulted in a significant reduction in the portosystemic gradient from 24.3 mm Hg +/- 5.7 to 9.3 mm Hg +/- 2.9 (P <.001). The hepatic artery peak systolic velocity and HABF increased significantly after TIPS creation, from 60.8 cm/sec +/- 26.7 to 121 cm/sec +/- 51.5 (P <.001) and from 254.2 mL/min +/- 142.2 to 507.8 mL/min +/- 261.3 (P <.001), respectively. The average incremental increase in HABF from pre-TIPS to post-TIPS was 253.6 mL/min +/- 174.2 and the average decremental decrease in portosystemic gradient was 15.0 mm Hg +/- 5.3, but there was no significant correlation (r = 0.04; P =.86) between the two. All shunts were patent at 30 and 90 days without sonographic evidence of shunt dysfunction. After TIPS creation, new or worsened encephalopathy developed in five patients at 30 days and in an additional three at 90 days. They were all successfully managed medically. Three patients (12.5%) died within 30 days of the TIPS procedure. The extent of incremental increase in HABF after TIPS was variable and did not correlate with the development of 30-day and 90-day encephalopathy (P =.41 and P =.83, respectively) or 30-day mortality (P =.2). CONCLUSIONS: HABF increases significantly after TIPS but is not predictive of clinical outcome. The significance of the incremental increase is yet to be determined.

Accuracy of CO(2) angiography in vessel diameter assessment: a comparative study of CO(2) versus iodinated contrast material in a porcine model.

PURPOSE: To compare, with use of intravascular ultrasound (IVUS) as an internal reference standard in a porcine model, arterial diameters measured from arteriograms obtained with use of CO(2) to those obtained with use of iodinated contrast material (ICM). MATERIALS AND METHODS: In nine pigs, digital subtraction angiograms (DSAs) were obtained in the aorta and iliac arteries to compare vessel diameters measured with use of CO(2) to those measured with use of ICM. These measurements were divided by measurements made with use of intravascular ultrasound (IVUS) to yield a DSA/IVUS ratio. Differences between ICM and CO(2) were compared with analysis of variance to assess the effect of location (aorta vs iliac), contrast material used (ICM vs CO(2)), and position (posteroanterior, right anterior oblique, or left anterior oblique). Secondary analysis compared measurements of dependent and nondependent iliac arteries and compared the use of hand-injected CO(2) to that of CO(2) injected by an injector. RESULTS: The DSA/IVUS ratio was 70.7% +/- 4.4% with ICM use and 69.6% +/- 6.3% with CO(2) use, which did not represent a significant difference (P =.311). Animal position had no effect (P =.477). Underestimation was worse in the iliac arteries than in the aorta (67.4% +/- 1.5% vs 71.4% +/- 1.7%; P =.038). There was no difference in nondependent (P =.163) arteries, but CO(2) underestimated dependent iliac artery size more than ICM did (66.3% +/- 4.8% vs 70.3% +/- 5.4%; P =.051). Vessel diameter was underestimated more with the CO(2) injector than with hand-injected CO(2) (64.3% +/- 2.3% vs 71.7% +/- 1.7%; P <.0001). CONCLUSION: There is no difference in diameter underestimation between CO(2) and ICM in this animal model. Hand-injection of CO(2) causes less underestimation of vessel diameter than does the CO(2) injector.

Renal arterial stenosis in renal allografts: retrospective study of predisposing factors and outcome after percutaneous transluminal angioplasty.

PURPOSE: To determine the predisposing factors to transplant renal arterial stenosis (TRAS) and assess the outcome of percutaneous transluminal angioplasty (PTA) as the primary treatment. MATERIALS AND METHODS: Of 831 renal allograft recipients (584 cadaveric, 247 living related) between January 1991 and December 1998, 72 had hypertension and/or renal dysfunction. All 72 underwent arteriography, and their medical charts were retrospectively reviewed. RESULTS: Prevalence of TRAS was 3.1% (26 of 831). Technical success rate of PTA was 94% (16 of 17), and clinical success rate was 82% (14 of 17). Those with renal dysfunction had a mean pre-PTA creatinine value of 2.6 mg/dL (230 micromol/L) +/- 0.5 (SD) versus a 1-week post-PTA value of 1.7 mg/dL (150 micromol/L) +/- 0.3 (P <.001). Of those with hypertension, all but one had substantial improvement in mean diastolic blood pressure. At 26.9 months mean follow-up in 16 patients with successful PTA, two stenoses reoccurred, and two grafts were lost to chronic rejection. TRAS was present in 14 of 45 end-to-side anastomoses and 12 of 27 end-to-end anastomoses (P =.31), and TRAS was more prevalent in cadaveric grafts (24 of 584) than in living related grafts (two of 247). In cadaveric grafts, the mean cold ischemia time was 29.0 hours +/- 6.9 in those with TRAS (n = 24), as compared with 25.5 hours +/- 8.1 in those with no TRAS (n = 39; P = .35). Seven of 17 patients with acute rejection and six of 35 with chronic rejection had TRAS. CONCLUSION: Primary treatment of TRAS with PTA has good intermediate-term results. TRAS is more prevalent in cadaveric allografts with long cold ischemia time.

Accuracy of CO2 angiography in vessel diameter assessment: a comparative study of CO2 versus iodinated contrast material in an aortoiliac flow model.

PURPOSE: Precise vessel sizing prior to endovascular intervention is critical to achievement of technical success. Diameter measurements obtained with CO2 and iodinated contrast material in an aortoiliac flow model were compared. MATERIALS AND METHODS: Aortoiliac flow was simulated in a compliant, silicone elastomer phantom of the aortoiliac system using an autoperfusion pump (flow volume, approximately 1100 mL/min; mean arterial pressure, 70-80 mm Hg at 80-90 cycles/minute) and a glycerol solution (40% by weight; viscosity 3.7 centipoise at 20 degrees C). Digital subtraction angiography was performed with the phantom in the anteroposterior (AP) plane and in three oblique planes with both CO2 and iodinated contrast material. Five sets of images for both CO2 and iodinated contrast material were obtained for each projection. Two readers independently performed vessel diameter measurements at seven sites (distal abdominal aorta, bilateral proximal and distal common iliac, and mid-external iliac arteries). The model was then evaluated with intravascular ultrasound (IVUS) using a 20-MHz imaging catheter. Actual diameter measurements were taken from the inner wall to inner wall in orthogonal planes at the same locations within the model, as described previously. Analysis was performed to determine local difference in measurements (t tests), difference when compared to the standard AP projection with iodinated contrast material (Dunnett's test) and inter-reader variability (Pitman's test). RESULTS: The contralateral iliac vessel segment did not opacify when imaging with CO2 in the 45 degrees obliquities; thus, 22 of 28 sites were available for comparison. At 18 of 22 (81.8%) sites, there was significant difference in vessel measurements (P < .01), with CO2 yielding a significantly larger diameter at 17 of 22 (77.3%) of the sites. The difference in mean diameter ranged from -1.28 to 4.47 mm. With use of the AP iodinated contrast material run as the standard, there were significant differences (P < .05) in vessel diameter at 17 of 22 (77.3%) and four of 21 (19%) sites for CO2 and iodinated contrast material respectively, with CO2 tending toward greater diameter measurements. Significant differences (P < .05) in variance between the two readers were present but occurred primarily with CO2 in the AP projection and iodinated contrast material in the 45 degrees left obliquity. With use of IVUS as the standard, there were significant differences (P < .05) in the measured vessel diameters with CO2 at nine of 22 (40.9%) of the sites and with iodinated contrast material at 17 of 28 (60.7%) of the sites. Of the measurements made with CO2, seven of nine (77.8%) of the measurements were of larger diameter than those obtained with IVUS. By contrast, of the measurements made with iodinated contrast material angiography, IVUS measured larger diameters in 16 of 17 (94.1%). CONCLUSION: CO2 angiography consistently yielded significantly larger vessel measurements when compared to both iodinated contrast angiography and WVUS. These results have important implications in regards to planning intervention based solely on CO2 angiography. Further evaluation is needed before recommending CO2 for vessel sizing in clinical practice.

Percutaneous transmyocardial intracardiac retroperfusion shunts: technical feasibility in a canine model.

PURPOSE: To test the technical feasibility of creating a left ventricle to coronary sinus shunt using endovascular techniques. MATERIALS AND METHODS: By means of a right jugular vein approach, a needle puncture was made from the coronary sinus to the left ventricle in 10 dogs. The tracts were balloon dilated and lined with 6-mm Wallstents. Shunt patencies, immediate and 4-hours later, were fluoroscopically assessed by contrast material injection into the left ventricle. Blood pressure, pulse, oxygen saturation, and cardiac rhythm were monitored. The dogs were then euthanized. Thoracic cavities and hearts were dissected and inspected. RESULTS: Technical success and immediate shunt patency were 100%. No cardiac dysrhythmias, electrocardiographic changes, or reduction in voltage potential were seen. Eight (80%) of the shunts were patent at 4 hours, one (10%) had thrombosed, and one dog died. Nine (90%) dogs had no pericardial hematoma and one (10%) had minimal pericardial blood from needle passes into the pericardial sac. The coronary sinuses were intact and no injuries to the valve leaflets or chordae tendineae were seen. The puncture sites were from the coronary sinus, 1-2 mm (mean, 1.3) from its auricular orifice, into the left ventricle, just below the inferior margin of the posterior leaflet of the mitral valve. One dog died at 3 hours with no preceding electrocardiographic evidence of impending demise. Autopsy showed no pericardial hematoma and the heart findings were no different from the other nine dogs. CONCLUSIONS: Creation of a left ventricle to coronary sinus shunt with use of endovascular techniques is technically feasible. Study of a transmyocardial intracardiac coronary retroperfusion shunt to deliver oxygenated blood to the ischemic myocardium is warranted.

Hemodialysis graft: use as access for upper and lower extremity arteriography and interventional procedures--initial experience.

Functioning hemodialysis grafts were used as access sites for peripheral vascular arteriography and interventional procedures. In 11 patients with end-stage renal disease and ischemia, upper extremity (n = 8) or lower extremity (n = 3) arteriography was performed successfully. Angioplasty and other interventional procedures were performed via the same route in two of the patients. No bleeding complications occurred, and all patients were ambulatory immediately after the procedure.

Tunneled jugular small-bore central catheters as an alternative to peripherally inserted central catheters for intermediate-term venous access in patients with hemodialysis and chronic renal insufficiency.

In 34 patients with chronic renal insufficiency or failure, 43 small-bore central catheters were placed via the internal or external jugular veins: right internal jugular vein, 28; left internal jugular vein, 14; right external jugular vein, one. Central venous access was achieved in all patients (mean catheter dwell time, 28 days; range, 3-99 days), with two minor complications (arterial puncture and catheter damage during suturing). Tunneled jugular small-bore central catheters are a vein-preserving alternative to peripherally inserted central catheters in this population.

Carbon dioxide angiography of the transplanted kidney: technical considerations and imaging findings.

OBJECTIVE: We evaluated the usefulness of carbon dioxide as the primary contrast material for renal transplant arteriography. CONCLUSION: Carbon dioxide accurately showed artery pathology including anastomotic and intrarenal stenoses, arteriovenous shunting, and diffuse arterial disease from chronic transplant rejection. Using carbon dioxide as a contrast agent reduced the volume of iodinated contrast material that needed to be used. There was no procedure-associated nephrotoxicity.

Abdominal aortic coarctation: CT, MRI, and angiographic correlation.

Abdominal aortic coarctation is an uncommon entity in the elderly. We present a case of abdominal aortic coarctation with computed tomography (CT), magnetic resonance imaging (MRI) and conventional angiographic correlation. CT and MR imaging detected an abnormal abdominal aorta distal to the origin of the celiac axis with the diagnosis of abdominal aortic coarctation confirmed by conventional angiography. Clinical presentation and diagnostic imaging findings depend on the level of the coarctation and its relationship to the renal vessels.

Renal lymphoma in Castleman's disease.

An unusual case of renal lymphoma occurring in a patient with Castleman's disease is presented. The radiographic features and the relationship to the lymphoproliferative disorders, Castleman's disease, and multicentric angiofollicular lymph node hyperplasia are described.