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.

Outcome of polyester cuff retention following traction removal of tunneled central venous catheters.

PURPOSE: To elucidate the factors that contribute to cuff retention during traction removal of tunneled catheters, as well as to determine the risk of complication associated with polyester cuff retention. MATERIALS AND METHODS: A total of 428 tunneled, cuffed catheters were removed with traction and local anesthesia. Polyester cuff retention was recorded when it occurred, and the effects of cuff retention were determined at a mean follow-up of 250 days. Statistical analysis was performed to determine the variables influencing cuff retention. RESULTS: Traction removal was successful in 428 (100%) patients. Of 428 catheters removed, 41 (10%) cuffs were retained. Silicone 10-F double-lumen and 9.6-F single-lumen catheters had a higher rate of cuff retention (27 [32%] of 84 and nine [39%] of 23, respectively) than did the split-tip polyurethane hemodialysis catheter (two [1%] of 196; P <.001). Cuff retention rates among other catheter types compared with that of the polyurethane catheter were not significantly different. Duration of catheter dwell did not significantly influence cuff retention. Of 41 retained cuffs, three required removal with cutdown for cuff migration to the exit site, which inhibited healing (n = 1); for suspected infection (n = 1); or for cosmetic purposes as requested by the patient (n = 1). The remaining patients had no complications associated with cuff retention. CONCLUSION: Traction removal of smaller-bore silicone catheters is more likely to result in cuff retention than removal of larger silicone and polyurethane catheters, and cuff retention is usually inconsequential.

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.

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.

Modified use of the arrow-trerotola percutaneous thrombolytic device for the treatment of thrombosed hemodialysis access grafts.

PURPOSE: To assess the safety and efficacy of using the Arrow-Trerotola percutaneous thrombolytic device (PTD) as the sole means of mechanical thrombolysis in hemodialysis access grafts, including in situ treatment of the arterial plug. PATIENTS AND METHODS: Fifty consecutive patients (22 women, 28 men; mean age, 58 years; mean graft age, 29 months), in whom mechanical thrombolysis of a thrombosed hemodialysis access graft using the PTD was planned, were included in the study. In all patients, the PTD was used to treat the arterial plug in situ at the arterial anastomosis, instead of using a Fogarty catheter to reposition the plug, as indicated in the PTD product labeling. Prospective data collection included demographic information, technical details of the procedure, immediate outcomes, and complications. Patients were followed for 3 months using definitions and data forms that were identical to those used in the original clinical trial of the PTD. A sample of procedures drawn from the PTD clinical trial database (n = 54) served as control. RESULTS: Immediate technical patency was 100%. Complications included arterial embolization (6% versus 2% control; P = NS; all successfully treated with backbleeding); venous rupture (6% versus 2% control; P = NS); and sepsis (n = 1), probably due to occult graft infection. Adjunctive therapy with an Adherent Clot catheter was needed in two procedures (4%). Three month patency using life-table analysis was 42% (versus 39% control; P = NS). The number of subsequent interventions (surgical/percutaneous) to the arterial limb of the graft did not differ from the PTD trial, and no native arterial stenoses were detected during the follow-up period. CONCLUSIONS: The PTD is safe and effective when used as the sole means of mechanical thrombolysis of hemodialysis grafts. Treating the arterial plug in situ with the PTD eliminates the need for a Fogarty or Adherent Clot catheter in 96% of procedures. A slight increase in arterial embolic complications was observed but these were easily treated with backbleeding.

Randomized comparison of high-flow versus conventional hemodialysis catheters.

PURPOSE: To evaluate short-term flow rates achieved with a new split-tip polyurethane hemodialysis catheter. PATIENTS AND METHODS: This was a prospective, randomized, nonblinded study. Patients referred for a tunneled-dialysis catheter received either a conventional silicone (Bard Hickman 13.5 F) if randomized to the control group, or a split-tip, high-flow polyurethane (MedComp AshSplit 14.5 F) catheter if randomized to the study group. Effective flow rates (QbEff) and recirculation were measured with use of ultrasonic dilution at pump settings (Qb) of 200, 300, 350 and 400 mL/min, as well as maximum Qb (QbMax, up to 500 mL/min) sustainable for at least 3 minutes. Measurements were repeated weekly for 6 weeks. Procedure times and initial and late complications were recorded. RESULTS: Twelve patients were enrolled in each group, 11 and eight completed the study in the test and control groups, respectively. Insertion complications, limited to the split-tip group, included asymptomatic air embolus (n = 1), prolonged tunnel bleeding (n = 2), and kinking (n = 2). Recirculation in both groups was low (mean < 6% at all flow rates). QbMax was 499 mL/min in the Ash group and 470 mL/min in the Hickman group. A repeated measures analysis of variance was used. Adjusted (for week) mean effective flow rates (Qbeff, mL/min) were as follows: at Qb = 200, Ash = 211, Bard = 211, P = .93; at Qb = 300, Ash = 301, Bard = 292, P = .28; at Qb = 350, Ash = 341, Bard = 314, P = .03; at Qb = 400, Ash = 375, Bard = 329, P = .01; at QbMax, Ash = 422, Bard = 359, P = .0005. CONCLUSION: Both catheters delivered flows within the acceptable range indicated by the Dialysis Outcomes Quality Initiative. The split-tip catheter is capable of higher flow rates (Qb and QbEff) compared with the conventional catheter, which may allow more efficient dialysis. Insertion complications appear to be higher with the new design.

Incidence and management of arterial emboli from hemodialysis graft surgical thrombectomy.

PURPOSE: To determine the incidence and significance of arterial emboli resulting from surgical thrombectomy/revision of hemodialysis grafts. This information may help in determining the significance and management of similar emboli resulting from percutaneous hemodialysis graft thrombolysis. PATIENTS AND METHODS: Patients undergoing surgical thrombectomy/revision of clotted hemodialysis grafts are studied with postoperative fistulography per institutional protocol whenever possible. For this retrospective study, all postoperative fistulograms from a 1-year period were reviewed for the presence of arterial emboli. Patients with documented arterial emboli were examined for evidence of hand/digital ischemia; only those patients with signs or symptoms of ischemia were treated. At clinical follow-up, repeated evaluation for hand/digital ischemia was performed. RESULTS: Ninety-one thrombectomy/revision procedures were performed during the study period. Postoperative fistulograms were obtained after 67 of these procedures in 32 patients. One patient complained of hand pain during dialysis prior to acquisition of the postoperative fistulogram. Arterial emboli were documented in eight patients (12%; brachial, n = 3; radial, n = 2; ulnar, n = 2; radial/ulnar, n = 1). The single symptomatic brachial embolus was percutaneously removed; no intervention was undertaken in the remainder. At mean follow-up of 14 months, no patient had developed hand or digital ischemia. Subsequent fistulograms demonstrated partial (n = 2) or complete (n = 2) resolution of the untreated emboli. CONCLUSION: Arterial emboli are a relatively common occurrence with surgical thrombectomy/revision. Conservative management appears to be indicated in asymptomatic patients.