Venous thrombosis associated with the placement of peripherally inserted central catheters.

PURPOSE: Peripherally inserted central catheters (PICCs) have become an essential component of the management of an increasing number of patients, including patients who may require hemodialysis. Reported symptomatic venous thrombosis rates associated with PICC lines are based on clinical signs and symptoms and range from 1% to 4%. The purpose of this study is to evaluate the true rate of thrombosis of upper extremity veins after the placement of PICCs and the potential impact on future access in hemodialysis patients. MATERIALS AND METHODS: A retrospective analysis was performed. Patients who had (i) normal findings during initial venography, (ii) PICC placement, and (iii) who underwent subsequent repeated venography were included. Age, sex, vein cannulated, catheter size, location, and incidence of thrombosis were analyzed. RESULTS: Three hundred fifty-four PICCs were placed in 119 patients. Of the 144 extremities, 137 had normal findings during initial venography. Of the 137 extremities, 32 developed thrombosis of the cannulated vein (or central veins) after initial PICC placement (23.3%). When all extremities with multiple PICC lines placed were considered, 52 developed thrombosis, for an overall thrombosis rate of 38%. The incidence of thrombosis by site was cephalic 57%, basilic 14%, and brachial 10%. No significant differences were noted in the rates of thrombosis by age, sex, or catheter size. CONCLUSIONS: There is a relatively high rate of venous thrombosis associated with PICCs, particularly cephalic thrombus. Because of the high rate of thrombosis associated with these catheters, an alternative mode of access should be considered in current or potential hemodialysis patients. All patients with a history of PICC line placement requiring dialysis access should undergo upper extremity venography prior to the placement of permanent access.

Creation of radiopaque thrombi for in vivo experiments.

PURPOSE: A number of percutaneous thrombectomy devices are undergoing investigation for treatment of patients with venous thromboembolism. Use of radiopaque thrombus to monitor thrombus delivery and assess thrombectomy has been previously reported. The purpose of this project was to quantitatively test the effect of mixing different ratios of blood and contrast material to facilitate maximum thrombus formation and radiopacity. MATERIALS AND METHODS: The following ratios of blood and contrast material were mixed: 2 mL blood to 8 mL contrast material (ratio = 0.25), 4 mL blood to 6 mL contrast material (ratio = 0.67), 6 mL blood to 4 mL contrast material (ratio = 1.5), and 8 mL blood to 2 mL contrast material (ratio = 4). Contrast material was added at day 0, 3, or 6. Each sample received one of two ionic contrast agents to opacify the clots. At day 14, thrombus mass and opacity were determined. RESULTS: Three combinations of blood and contrast material produced maximum thrombus and radiopacity. These were sodium iothalamate 30% with a ratio of 4 with contrast material added on day 0 and sodium iothalamate 60% with a ratio of 1.5 with contrast material added on day 3 or 6. CONCLUSIONS: When forming radiopaque thrombi, significant differences can result from the ratio of blood to contrast material used. Contrast material type can also affect radiopacity and mass formed. The use of optimal ratios of blood to contrast material should maximize device evaluation with minimal wasting of valuable resources such as test subjects, physician time, and equipment.

Single-specimen bile cytology: a prospective study of 80 patients with obstructive jaundice.

PURPOSE: To determine the sensitivity, specificity, and charges associated with single-specimen bile cytologic study in patients with obstructive jaundice. MATERIALS AND METHODS: Eighty consecutive patients with presumed malignant biliary strictures underwent percutaneous biliary drainage (PBD). Cytologic evaluation was performed on a single bile specimen from each patient collected at the time of the PBD. Final diagnoses were obtained from either percutaneous (n = 14) or surgical (n = 66) histologic specimens (gold standard). Both data sets were then compared to determine the sensitivity and specificity of bile cytology. The charges associated with bile cytodiagnosis were compared to those for other biopsy procedures utilized in the same setting. RESULTS: Eighty bile specimens were obtained with a mean of 14 mL (range, 3-65 mL) per patient with 79 (99%) specimens adequate for cytologic processing. Eleven (13%) specimens were acellular. The overall sensitivity was 15% and specificity was 100%; these values were not dependent on the volume of the bile specimen (P > .10) or type of malignancy (P = .10). For bile cytodiagnosis, the mean charge was $160 and the successful biopsy rate (true-positive plus true-negative results/total number procedures) was 27%. CONCLUSION: Single-specimen bile cytology has a low sensitivity; however, because of its convenience, simplicity, atraumatic nature, and low relative charge versus comparable procedures, it may be useful as an adjunct to PBD in patients with suspected malignant biliary disease.

Role of CT angiography in the preoperative evaluation for laparoscopic nephrectomy.

Laparoscopic nephrectomy (LN) was recently introduced as a minimally invasive alternative to open nephrectomy in living related renal donation. Because of the limited field of view available with laparoscopic techniques, the role of preoperative radiologic evaluation in LN has expanded to include anatomic definition of the renal arteries, collecting system, renal parenchyma, and renal venous anatomy. Computed tomographic (CT) angiography has proved to be a minimally invasive alternative to conventional angiography in the preoperative evaluation of living related renal donors. CT angiography has been shown to have an accuracy comparable to that of conventional angiography in predicting renal arterial anatomy. In addition, CT angiography provides comprehensive definition of the renal vascular anatomy including the location, size, and length of the renal, adrenal, gonadal, and lumbar veins. Dual-phase spiral CT combined with three-dimensional CT angiography constitute a single, minimally invasive procedure that can provide a complete preoperative evaluation of potential living related renal donors prior to LN. Comprehensive anatomic depiction of the renal arterial and venous supplies aids in surgical planning and helps avoid potential complications.