Time to hemostasis after traction removal of tunneled cuffed central venous catheters.

PURPOSE: Many patients undergo placement of tunneled cuffed central venous catheters (TCCVCs) for indications including administration of medical therapy and hemodialysis. They are removed when no longer needed or if there is a device complication. There is no consensus regarding the necessity of routine preremoval coagulation studies or platelet count, so this study was performed to determine if abnormal coagulation status affects the time to hemostasis (TH) after traction removal of TCCVCs. MATERIALS AND METHODS: Adult patients referred to our group for removal of a TCCVC placed via a jugular or subclavian route were considered candidates for inclusion. Blood was submitted for evaluation of prothrombin time (PT) and International Normalized Ratio (INR), activated partial thromboplastin time (aPTT), and platelet count. Catheters were removed with the traction technique, and presence of hemostasis was assessed at 5-minute intervals of manual compression. RESULTS: Between November 19, 2001, and April 20, 2004, 179 subjects were enrolled and completed the study. There were 165 subjects in whom TH was within the first 5-minute interval and 14 in whom more than 5 minutes was required. Statistically significant factors associated with prolonged TH were primary diagnosis of end-stage renal disease (P = .005), use of antiplatelet agents (P = .03), and procedure performed by a "low-volume" operator (P = .002). CONCLUSIONS: Routine preremoval evaluation of coagulation parameters is not necessary. Patients who are likely to have abnormal platelet function but not abnormal platelet number appear to be at risk for prolonged TH, but even in those cases, the THs are rarely more than 15 minutes.

Renal interventions after abdominal aortic aneurysm repair using an aortic endograft with suprarenal fixation.

BACKGROUND: Our aim was to determine whether suprarenal fixation in endografts compromises renal artery (RA) flow and whether subsequent RA intervention is precluded by the stent struts. METHODS: Prospectively acquired data from 104 patients with endovascular aneurysm repair (EVAR) of an abdominal aortic aneurysm using the Zenith endograft (Cook, Inc., Bloomington, IN) were analyzed. The Zenith device uses a 26-mm, uncovered, barbed Z stent for suprarenal function. RESULTS: No RA stenosis, occlusion, or infarction resulted from the suprarenal stent. In 3 of 104 (2.9%) patients, RA compromise (2 stenoses, 1 occlusion) was caused by impingement of graft material on the lowermost RA. The 2 RA stenoses were stented successfully at 1 and 7 months post-EVAR. Six of 104 (5.8%) patients developed late stenoses unrelated to the endograft: all were stented successfully from 19 to 36 months after EVAR. One patient with severe RA stenosis had balloon angioplasty pre-EVAR and then was stented electively 6 weeks post-EVAR. CONCLUSIONS: Our data show that the suprarenal fixation of the Zenith aortic endograft does not cause RA stenosis, occlusion, or infarction, nor does it preclude post-EVAR renal artery intervention.

Severe thrombocytopenia due to hypersplenism successfully treated with partial splenic embolization in preoperative management.

Hypersplenism is a known complication of portal hypertension secondary to cirrhosis of the liver. Although thrombocytopenia secondary to hypersplenism does not cause clinically significant hemostatic defect, it may need to be addressed in selective circumstances, such as preoperative preparation for a surgery. This report describes a 30-year-old male with a history of cirrhosis of the liver and hypersplenism who had a recurrence of craniopharyngioma. A platelet count of 40 x 10(9)/L limited his treatment options. A stereotactic injection of radioactive P32 into the tumor was planned but was thought not to be feasible because of the thrombocytopenia. The thrombocytopenia responded favorably to partial splenic embolization, and the patient underwent successful stereotactic injection of radioactive P32 into the tumor.

Suspected acute pulmonary embolism: evaluation with multi-detector row CT versus digital subtraction pulmonary arteriography.

PURPOSE: To determine diagnostic accuracy of four-channel multi-detector row computed tomography (CT) in emergency room and inpatient populations suspected of having acute pulmonary embolism (PE) who prospectively underwent both CT and pulmonary arteriography (PA). MATERIALS AND METHODS: Patients referred for PA to assess suspected PE were eligible. Institutional review board approval and written informed consent were obtained. All patients underwent CT and PA within a 48-hour period. For CT, 4 x 2.5-mm collimation was used. Three readers independently evaluated each study for PE presence. PE status, vessel level, and lobar location were determined by means of majority rule, and interobserver agreement (kappa) was calculated for PE status, as assessed with each modality. Sensitivity and specificity of CT were calculated by using PA as the reference standard. Two radiologists later reviewed false-positive CT studies. RESULTS: The study group comprised 93 patients (median age, 56 years; range, 19-88 years). Sensitivity, specificity, and accuracy of CT were 100%, 89%, and 91%, respectively. kappa values were 0.71 and 0.83 for CT and PA, respectively, and were not significantly different between modalities. At PA, 18 patients (19%) had PE at 50 vessel levels (five main and/or interlobar, 24 segmental, and 21 subsegmental), 17 (94%) of which had PE at multiple sites. At CT, 26 patients (28%) had PE at 71 vessel levels (24 main and/or interlobar, 33 segmental, and 14 subsegmental). Twenty patients (77%) had PE at multiple sites. Review of eight false-positive CT studies showed an appearance highly suggestive of acute PE in three patients, chronic PE in one, and no PE in three; one study was inconclusive. CT better demonstrated large-level vessel involvement (P < .01), while PA better demonstrated small-level vessel involvement (P < .01). CONCLUSION: Multi-detector row CT has an accuracy of 91% in the depiction of suspected acute PE when conventional PA is used as the reference standard.

Embolization of large gastric varices using vena cava filter and coils.

A 40-year-old male with alcoholic cirrhosis and portal hypertension presented with acute variceal hemorrhage. Abdominal CT scan and endoscopy revealed large gastric varices. The patient underwent a TIPS procedure. Portal venography demonstrated persistent filling of the large gastric varices with associated high-flow spontaneous splenorenal shunt. Because of the large size of the varices, a Simon-Nitinol filter was used in conjunction with multiple embolization coils to enable successful occlusion of the varices.

Management of catheter-induced venous thrombosis.

Catheter-induced venous thrombosis remains a significant problem in current clinical practice. A high level of biocompatibility of the materials used to manufacture the existing venous access devices has not eliminated catheter-induced venous thrombosis. Similarly, catheter bonding with anticoagulants or their systemic use, while in some instances having a favorable effect on the incidence, has not eliminated this problem. The focus of this article is on discussion of the various factors that influence formation of catheter-induced venous thrombosis. Also discussed is the management of this clinical problem, and a useful algorithm is outlined.

Randomized comparison of split tip versus step tip high-flow hemodialysis catheters.

BACKGROUND: Our purpose was to compare the function and complications of two high-flow polyurethane hemodialysis catheters. METHODS: This prospective, randomized trial compared the Ash-Split (MedComp) and Opti-Flow (Bard Access Systems) catheters. All patients referred for tunneled hemodialysis catheter placement were offered entry in the study, provided they met inclusion criteria. Catheters were placed by interventional radiologists using ultrasound and fluoroscopic guidance. Procedure time and initial complications were recorded. Effective (QbEff) catheter flow rates and recirculation were studied at baseline, one month, three and six months using ultrasonic dilution (Transonic) at various pump speeds (Qb). Episodes of catheter malfunction and infection were recorded. Catheter removal or six months was the study endpoint. RESULTS: A total of 132 patients were enrolled in the trial. The groups did not differ as to age, sex distribution, height or weight (P> 0.05). Initial complications included kinking resulting in catheter failure (Optiflow N = 3), and tunnel bleeding (Optiflow N = 1; Ash N = 3). Adjusted mean flow rates (QbEff) at Qb300 were 299 mL/min Ash and 305 mL/min Optiflow (P = 0.06), at Qb400 were 365 mL/min Ash and 382 mL/min Optiflow (P = 0.01), and at QbMax were 414 mL/min Ash and 433 mL/min Optiflow (P = 0.03). Recirculation was significantly higher with the Optiflow catheter at most measurement points. Total late complications were lower in the Ash group (P = 0.04), and catheter survival was significantly higher in the Ash group (P = 0.02). CONCLUSIONS: Both catheters can deliver flow rates well beyond those recommended by the Dialysis Outcomes Quality Initiative. While the Optiflow delivered higher flow rates at some measurement points, this was offset by higher recirculation. The Ash catheter showed a long-term survival advantage and fewer late complications.

Use of balloon-expandable stents in transjugular intrahepatic portosystemic shunts in cases of Wallstent endoprosthesis technical failure and revision of shunt stenosis.

Thirteen patients underwent placement of a balloon-expandable stent either at initial transjugular intrahepatic portosystemic shunt (TIPS) creation (n = 3) because of immediate technical failure of the Wallstent or at shunt revision because of failure of the Wallstent to reduce the portosystemic gradient

Percutaneous imaging-guided access for the treatment of calculi in continent urinary reservoirs.

PURPOSE: To describe our long-term experience with percutaneous access to continent urinary reservoirs for calculus removal. PATIENTS AND METHODS: A retrospective study of 13 procedures in 10 patients was performed. In 2 of the 13 procedures, access and calculus removal was performed in a single session. In the other 11 procedures, initial access was obtained using ultrasonography, fluoroscopy, and/or computed tomography. The patients then returned at a later date for a second step where the access was dilated and the calculi were removed. RESULTS: Access was achieved successfully in all cases with no complications. At mean follow-up time of 13.6 months (range 1-94 months) one patient had died of complications unrelated to her continent urinary reservoir. Another patient had been placed on suppressive antibiotics for recurrent calculi. The remaining patients were stone free and without late complication. CONCLUSIONS: Percutaneous removal of reservoir calculi can be performed safely, avoiding potential injury to the continence valve mechanism by a direct cystoscopic approach. We propose a two-stage procedure using CT guidance for initial access as the preferred technique.