Power injection of contrast media using central venous catheters: feasibility, safety, and efficacy.

OBJECTIVE: This study evaluates the feasibility, safety, and efficacy of power-injecting IV contrast media through central venous catheters for CT examinations. SUBJECTS AND METHODS: Two hundred ninety-five CT examinations were performed during an 18-month period in 225 patients with indwelling central venous catheters. Patients were randomized to power injection either through peripheral IV catheter or through central venous catheter. Feasibility was defined as the percentage of patients with contrast material injected successfully through the randomized access route. Safety was evaluated by comparing patients with complications. Efficacy was evaluated by comparing contrast enhancement of the thoracic aorta, pulmonary artery, abdominal aorta, and liver. RESULTS: Two hundred nine patients had randomization data recorded. One hundred three (94%) of 109 patients were successfully injected through their indwelling catheter compared with 42 (42%) of 100 through a peripherally placed IV catheter (p < 0.001). After reassignment for unsuccessful access, 174 patients underwent central venous catheter injection, and 51, peripheral IV catheter injection. No statistically significant difference was noted in the complications between the central venous catheter and peripheral IV catheter groups. Enhancement was greater in the thoracic aorta, pulmonary artery, and liver for the peripheral IV catheter group (p < 0.03). CONCLUSION: Power injection of contrast media through central venous catheters for CT examinations is feasible and safe when set hospital guidelines and injection protocols are followed. This technique provides an acceptable alternative in patients without adequate peripheral IV access when bolus contrast enhancement is desired.

3-dimensional volume rendered computerized tomography for preoperative evaluation and intraoperative treatment of patients undergoing nephron sparing surgery.

PURPOSE: Computerized tomography (CT) is the diagnostic and staging modality of choice for renal neoplasms. Existing imaging modalities are limited by a 2-dimensional (D) format. Recent advances in computer technology now allow the production of high quality 3-D images from helical CT. Nephron sparing surgery requires a detailed understanding of renal anatomy. Preoperative evaluation must delineate the relationship of the tumor to adjacent normal structures and demonstrate the vascular supply to the tumor for the surgeon to conserve as much normal parenchyma as possible. We propose that helical CT combined with 3-D volume rendering provides all of the information required for preoperative evaluation and intraoperative management of nephron sparing surgery cases. We prospectively evaluated the role of 3-D volume rendering CT in 60 patients undergoing nephron sparing surgery for renal cell carcinoma at the Cleveland Clinic Foundation. MATERIALS AND METHODS: Triphasic spiral CT was performed preoperatively in 60 consecutive patients undergoing nephron sparing surgery for renal neoplasms. A 3 to 5-minute videotape was prepared using volume rendering software which demonstrated the position of the kidney, location and depth of extension of the tumor(s), renal artery(ies) and vein(s), and relationship of the tumor to the collecting system. These videotapes were viewed by a radiologist and urologist in the operating room at surgery, and immediately correlated with surgical findings. Corresponding renal arteriograms of 19 patients were retrospectively compared to 3-D volume rendering CT and operative findings. RESULTS: A total of 97 renal masses were identified in 60 cases evaluated with 3-D volume rendering CT before nephron sparing surgery. There were no complications related to the 3-D protocol and 3-D rendering was successful in all patients. The number and location of lesions identified by 3-D volume rendering CT were accurate in all cases, while enhancement and diagnostic characteristics were consistent with pathological findings in 95 of 97 tumors (98%). Of 77 renal arteries identified at surgery 74 were detected by 3-D volume rendering CT (96%). Helical CT missed 3 small accessory arteries, including 1 in a cross fused ectopic kidney. All major venous branches and anomalies were identified, including 3 circumaortic left renal veins. Of 69 renal veins identified at surgery 64 were detected by 3-D volume rendering CT (93%). All 5 renal veins missed by CT were small, short, duplicated right branches of the main renal vein. Renal fusion and malrotation anomalies were correctly identified in all 4 patients. CONCLUSIONS: The 3-D volume rendering CT accurately depicts the renal parenchymal and vascular anatomy in a format familiar to most surgeons. The data integrate essential information from angiography, venography, excretory urography and conventional 2-D CT into a single imaging modality, and can obviate the need for more invasive imaging. Additionally, the use of videotape in an intraoperative setting provides concise, accurate and immediate 3-D information to the surgeon, and it has become the preferred means of data display for these procedures at our center.

Results of the clinical evaluation of atypical glandular cells of undetermined significance (AGCUS) detected on cervical cytology screening.

OBJECTIVE: To determine the clinical significance of and underlying pathology among patients with atypical glandular cells of undetermined significance (AGCUS) identified on cervical Pap smear screening. METHODS: The computerized files of the Cleveland Clinic Foundation cytology laboratory were searched from 1990 to 1994 to identify all patients with AGCUS. Patients with other significant cytologic diagnoses were considered separately from patients whose only significant finding was reported to be AGCUS. Retrospective chart review was completed to identify associated conditions and to record the results of the clinical evaluations of these patients. RESULTS: One hundred thirty-six patients were identified among the 68,368 (0.2%) specimens from this 5-year period in contrast to 3078 (4.5%) patients with atypical squamous cells (ASCUS). Mean patient age was 43.7 years (range 20-78). Among 77 patients without other significant cytologic findings in addition to AGCUS, without prior gynecologic cancer and who had a recorded gynecologic evaluation, 13 patients (17%) were diagnosed with the following lesions: two (3%) invasive cervical adenocarcinomas, three cervical adenocarcinomas in situ (4%), three grade 1 cervical intraepithelial neoplasms (CIN) (4%), four grade 2-3 CIN (5%), and one (1%) endometrial adenocarcinoma. Additionally, in subsequent follow-up examinations two patients were diagnosed with cervical adenocarcinoma in situ, one with invasive adenocarcinoma of the cervix and one with diffusely metastatic pancreatic cancer. CONCLUSIONS: AGCUS on cervical cytologic screening, even in the absence of other associated cytologic findings, is associated with substantial underlying uterine pathology including at least 4% (95% confidence interval (CI) 0.8%, 11.0%) invasive cancers and 13% (95% CI 6.4%, 22.6%) precancerous lesions. Cervical colposcopy, endocervical curettage, and endometrial biopsy are recommended for the complete evaluation of AGCUS.