Gary D. Hartwell

Safety and efficacy of ERCP in pregnancy

BACKGROUNDnCholedocholithiasis during pregnancy increases the risk of morbidity and mortality for both fetus and mother because of cholangitis and pancreatitis. ERCP has been advocated as safe and effective in pregnant women, but fetal radiation exposure is not routinely monitored. The aim of this study was to record fetal exposure to ionizing radiation during ERCP and to assess outcome.nnnMETHODSnSeventeen ERCPs were performed in pregnant women between January 1995 and August 2003. Techniques to minimize fluoroscopy were used, and fluoroscopy times were recorded. Thermoluminescent dosimeters affixed to the skin of the mother were used to estimate fetal radiation exposure.nnnOBSERVATIONSnMean gestational age was 18.6 (8.9) weeks (range 5-33 weeks). Mean fluoroscopy time was 14 (13) seconds (range 1-48 seconds). Estimated fetal radiation exposure was 40 (46) mrad (range 1-180 mrad). There was a correlation between fluoroscopy time and radiation exposure, but there was a wide range of radiation exposure for individual fluoroscopy times. Complications included post-sphincterotomy bleeding in one patient (controlled by hemoclip placement) and post-ERCP pancreatitis in one patient that necessitated 3 days of hospitalization. Two women developed third-trimester preeclampsia, and labor was induced in both. Thirteen of the 15 patients who delivered were contacted and they confirmed that their child was in good health.nnnCONCLUSIONSnERCP with modified techniques is safe during pregnancy. Dosimetry should be routinely recorded.

Reducing the Discomfort of Lidocaine Administration through pH Buffering

PURPOSEnA prospective, double-blind study was undertaken to evaluate the effect of using a buffered lidocaine solution on the perception of pain experienced by a patient during its intradermal injection.nnnPATIENTS AND METHODSnOne hundred fifty patients undergoing diagnostic angiographic and interventional procedures at the authors institution were randomly assigned to receive a 1-mL aliquot of one of three lidocaine solutions: plain 1% lidocaine, 1% lidocaine diluted with normal saline in a 10:1 ratio, and 1% lidocaine diluted with 8.4% sodium bicarbonate in a 10:1 ratio. The lidocaine solutions were administered intradermally over 10-15 seconds. A numerical value was placed on the patients perception of pain, separate from that associated with the 25-gauge needle insertion, with use of a linear visual analog scale.nnnRESULTSnMean pain scores were as follows: for the 1% lidocaine solution, 2.83 +/- 2.60; for 1% lidocaine plus normal saline solution, 2.89 +/- 2.34; and for 1% lidocaine plus sodium bicarbonate solution, 1.37 +/- 1.73 (P = .0018).nnnCONCLUSIONnBuffering lidocaine significantly decreased the discomfort associated with its administration as a local anesthetic.

Flow characteristics of peripherally inserted central catheters

PURPOSEnClinical applications of peripherally inserted central catheters (PICCs) are limited by the relatively small lumina and long lengths of these devices. Quantitative analysis of the flow capabilities of a variety of PICCs was performed to aid in deciding which patients should have a PICC and in selecting the appropriate catheter.nnnMATERIALS AND METHODSnSixteen different PICCs from six manufacturers were infused at flow rates of 25-270 mL/h. Infusions were performed with distilled water, normal saline, total parenteral nutrition solution, intralipids, and blood. Flow versus pressure curves were generated for each PICC and infusate. Additional catheter data recorded included the working length, outer diameter (OD), and inner diameter (ID) of the PICCs.nnnRESULTSnBecause of the thin wall construction of polyurethane catheters, PICCs made from polyurethane showed much better flow rates than silicone PICCs of a comparable OD. The measured ODs of the PICCs were 4-6 F, whereas the IDs ranged from 0.012 to 0.032 inch. Because of the small ID of some PICCs, infusing blood or intralipids is not practical.nnnCONCLUSIONnThere is significant variability in the flow capabilities of available PICCs. Many of the PICCs require pressures greater than those that can be generated by commercially available infusion pumps. Matching PICC characteristics to the desired application will avoid many of the clinical problems currently encountered with PICCs.

Gadolinium-based contrast agents in angiography and interventional radiology.

Gadolinium is useful as an alternative contrast agent for diagnostic angiographic and interventional procedures in patients with renal insufficiency or a history of a severe reaction to iodinated contrast material. Gadolinium usually is used as a problem solver to answer specific diagnostic questions or guide interventional procedures that cannot adequately be defined with CO2 angiography. Because of dose limitations with Gd, careful planning is required prior to its use with angiography or interventional procedures.

Three-Dimensional Rotational Angiography of the Inferior Vena Cava as an Adjunct to Inferior Vena Cava Filter Retrieval

The objective of this study was to explore the role of three-dimensional (3-D) rotational angiography (RA) of the inferior vena cava (IVC; 3-D CV) before filter retrieval and its impact on treatment planning compared with standard anteroposterior cavography (sCV). Thirty patients underwent sCV and 3-D CV before IVC filter retrieval. Parameters assessed were: projection of filter arms or legs beyond the caval lumen, thrombus burden within the filter and IVC, and orientation of the filter within IVC. Skin and effective radiation doses were calculated. Statistical analysis was performed using paired Student t test and nonparametric McNemar’s test. Standard anteroposterior cavography detected 49 filter arms or legs projecting beyond the caval lumen in 25 patients. Three-dimensional CV demonstrated 89 filter arms or legs projecting beyond the caval lumen in 28 patients. Twenty-two patients had additional filter arms or legs projecting beyond the caval lumen detected on 3-D CV that were not detected on sCV (pxa0<xa00.001). Filter apex tilt detection differed significantly (pxa0<xa00.001) between sCV and 3-D CV, with 3-D CV being more accurate. The filter apex abutted the IVC wall in 10 patients (33%) on 3-D CV, but this was diagnosed in only 3 patients (10%) with sCV. Thrombus was detected in 8 patients (27%), 1 thrombus of which was seen only on 3-D CV, and treatment was changed in this patient because of thrombus size. Mean effective radiation doses for 3-D CV were approximately two times higher than for sCV (1.68 vs. 0.86xa0mSv), whereas skin doses were three times lower (12.87 vs. 35.86xa0mGy). Compared with sCV, performing 3-D CV before optional IVC filter retrieval has the potential to improve assessment of filter arms or legs projecting beyond the caval lumen, filter orientation, and thrombus burden.

Interventional uroradiologic procedures performed using gadodiamide as an alternative to iodinated contrast material

Three patients with either a history of severe allergic reactions to iodinated contrast or marked renal insufficiency underwent interventional uroradiologic procedures using full-strength gadodiamide (Gd) as a contrast agent in place of iodinated contrast material. The procedures were percutaneous access for nephrostolithotomy, antegrade pyelography with placement of a nephroureteral stent, and a diagnostic nephrostogram with exchange of a nephroureteral stent. Gd was visualized fluoroscopically and produced satisfactory digital radiographs without allergic reaction or worsening renal function. Gd can be useful in guiding interventional uroradiologic procedures when iodinated contrast material is contraindicated.