MEDLINE Abstracts: Interventional Radiology

April 10, 2002

MEDLINE Abstracts: Interventional Radiology

What's new concerning interventional radiology? Find out in this easy-to-navigate collection of recent MEDLINE abstracts compiled by the editors at Medscape.

Skehan SJ, Malone DE, Buckley N, et al
Radiology. 2000 Sep,216(3):653-659

Purpose: To evaluate the safety and effectiveness of a systematic protocol for sedation and analgesia in interventional radiology.
Materials and Methods: Ninety-one adult patients underwent 113 abdominal interventional procedures. Fentanyl citrate and midazolam hydrochloride were administered in one to five steps (A, B, C, D, E) until the patient was drowsy and tranquil at the effective loading dose (ELD). Doses per step were as follows: A, fentanyl 1 mug per kilogram of body weight; B, midazolam 0.010-0.035 mg/kg; C, repeat dose in A; D, repeat half the dose in B; and E, midazolam 1-2-mg boluses (maximum, 0.15 mg/kg).
Results: The ELD was reached in no procedure after step A, in 70 after B, in 23 after C, and in 18 after D. Step E was needed in two procedures. The mean maximum pain score (scale of 0 to 10) was 3.4; pain scores in 85 (75%) procedures were 4 or less (discomforting). Severe pain occurred in seven (6%) procedures. Hypoxia (oxygen saturation < 90%) occurred in 11 (22%) procedures performed in patients breathing room air and four (6%) performed in those breathing supplemental oxygen (P: =.04). All patients responded to supplemental oxygen.
Conclusion: This stepwise "ABCDE protocol" allows safe and effective sedation of patients. It is easy to use and may be useful in training radiology residents, staff, and nurses in the techniques of sedation and analgesia. Supplemental oxygen should be used routinely.

Mueller PR, Biswal S, Halpern EF, et al
Radiology. 2000 Jun,215(3):684-8

Purpose: To prospectively assess patient anxiety, understanding of the procedure being performed, perception of pain level, and satisfaction with medication given for a variety of diagnostic and therapeutic vascular and visceral (nonvascular) interventional procedures.
Materials and Methods: The authors interviewed 204 patients before and after they underwent an interventional radiologic procedure. Patients responded to a series of questions by using a visual analog scale. Patients were grouped according to (a) their level of experience with the procedure and (b) the type of procedure performed (diagnostic or therapeutic visceral procedure or diagnostic or therapeutic vascular procedure).
Results: Patients who had previous experience with a procedure, whether visceral or vascular, were less anxious, had more understanding, and anticipated less pain than did those who did not have experience with a procedure. Patients who had only local anesthesia for visceral biopsy experienced greater pain than did those who had both local and intravenous anesthesia. Satisfaction scores, however, were similar throughout all groups.
Conclusion: Patients have a moderate amount of anxiety about interventional procedures and anticipate some discomfort. Most patients have a high level of satisfaction despite the amount of pain they experience during the procedure. Patients experienced with a procedure tend to have a greater understanding of the procedure and less anxiety.

Benz CA, Jakob P, Jakobs R, et al
Endoscopy. 2000 May,32(5):428-31

Hemorrhage from the pancreatic duct, i.e. hemosuccus pancreaticus (HP), is a rare cause of gastrointestinal bleeding. Pancreatic hemosuccus is usually due to the rupture of an aneurysm of a visceral artery, most likely the splenic artery, in chronic pancreatitis. Other causes of HP are rare. We present a case of HP in a female patient with no history but with positive findings of chronic calcifying pancreatitis upon ultrasonographic investigation, computed tomography scan, and endoscopic retrograde cholangiopancreatography. With detectable fresh blood in the descending duodenum, angiography of the celiac artery revealed an aneurysm of the splenic artery as the suspected cause of intermittent bleeding from the pancreatic duct. The treatment is traditionally surgical or by interventional radiological means. This is the first case described in the literature in which interventional radiological therapy involved implantation of an uncoated metal Palmaz stent in the splenic artery. In the follow-up of 18 months no relapse of HP was observed.

Jacob AL, Messmer P, Kaim A, et al
Invest Radiol. 2000 May,35(5):279-88

Rationale And Objectives: To develop and test an image-guided navigation system in which the base of reference is taken from the imaging modality, here, a helical CT scanner.
Methods: An optical digitizer together with a calibration device is used to measure the transformation matrix between the digitizer reference system and a CT reference system. During intervention, it tracks radiological and surgical tools with tool references. A specific software visually integrates the current tool position with the corresponding image information. In vitro accuracy tests were performed.
Results: With helical CT, freehand positioning accuracy was 1.9 +/- 1.1 mm (mean +/- SD) in vitro (n = 718).
Conclusions: The navigation system developed by the authors appears to be feasible for radiological interventions as well as for minimally invasive surgery. It is not limited to a certain procedure, can be used in every region of the body, and is functional after imaging. Intraprocedural scans can be integrated immediately.

Razzaq R, England RE, Martin DF
Clin Radiol. 2000 Feb,55(2):131-5

Aims: To evaluate the efficacy of interpleural analgesia during percutaneous transhepatic biliary procedures.
Method: With the patient lying in the left lateral decubitus position a right sided interpleural catheter was sited at a chosen point between the 6th and 9th interspaces. Lignocaine was injected to provide a splanchnic and intercostal nerve block. The technique of interpleural block (IPB) is described. Assessment of the pulse, BP and O(2)saturation during the subsequent biliary procedure was made. The patient evaluated the maximum degree of pain felt during the biliary procedure according to a four-point pain scale (0-3). The nurse and radiologist also gave an objective assessment of the pain score.
Results: An IP catheter was successfully placed in 22 patients, one patient having the IPB on two occasions. Siting of the IP catheter failed in three patients. Good analgesia with no requirement for further analgesia or sedation was achieved in 11 patients on 12 occasions. Seven patients required additional small doses of analgesia for mild pain during the biliary procedure. IPB failed in four patients who required additional analgesia and sedation. No complication of the IPB technique occurred in our patient group.
Conclusion: IPB is a safe and relatively effective method for analgesia during transhepatic percutaneous biliary procedures. Copyright 2000 The Royal College of Radiologists.

Caridi JG, West JH, Stavropoulos SW, et al
AJR Am J Roentgenol. 2000 Feb,174(2):363-6

Objective: The necessity of obtaining a postprocedure chest radiograph after central venous access using the upper extremity or internal jugular veins and interventional radiologic techniques was evaluated.
Subjects and Methods: A prospective study of 937 consecutive central venous access procedures in interventional radiology using the internal jugular veins or upper extremities was performed from June 1995 through September 1997. Established interventional radiologic techniques were used to place various ports (n = 34) and tunneled (n = 670) and nontunneled (n = 233) catheters. All catheters were positioned using fluoroscopy and readjusted if necessary before termination of the procedure. Afterward, a chest radiograph was obtained with the patient upright to evaluate catheter position and possible procedural complications. Procedural complications and manipulations or interventions that resulted from the radiographic findings were noted. In addition, nursing time for acquisition of the chest radiograph was recorded.
Results: We found seven procedural complications (four air emboli, two pneumothoraces, one innominate vein laceration) significant enough to alter the patient's treatment. These complications were apparent during the examination. Postprocedure chest radiography failed to reveal any unknown complications and revealed only one catheter sufficiently malpositioned to require manipulation. The amount of nursing time to acquire postprocedure chest radiographs ranged from 8 to 40 min (mean, 23 min) per patient.
Conclusion: When imaging guidance and interventional radiologic techniques are used for upper extremity and internal jugular central venous access, performing postprocedure chest radiography yields little benefit.

Ruiz-Cruces R, Perez-Martinez M, Tort Ausina I, et al
Eur J Radiol. 2000 Jan,33(1):14-23

Nowadays, the radiological risk from simple X-ray procedures is well known. The purpose of this work has been to estimate the population risk from digital angiographic and interventional procedures and to compare it with the one from simple procedures in the same population. The population risk has been estimated according to the following quantities: genetically significant dose, somatic significant dose, collective effective dose, annual per caput effective dose and detriment. These have been estimated from dose area product and organ dose. Organ dose values were estimated with the Eff-Dose software. A population of 605410 people were included in the study. In 1996, 1312 patients were to digital interventional vascular procedures in Malaga, and 159 of them were selected in this research project to obtain the dose area product and organ dose. The results obtained for the quantities evaluated are: genetically significant dose, 4.1 microGy; somatic significant dose, 0.9 mSv; collective effective dose, 11.65 person-Sv: annual per caput effective dose, 0.02 mSv and detriment, 0.65 radiogenic cancers per year. These procedures supply a high radiation dose, so they should have a greater contribution to population dose and risk than simple examinations. However, our results indicate just the opposite.

Kerber CW, Wong W
Neurosurg Clin N Am. 2000 Jan,11(1):85-99, viii-ix

Treating patients with brain arteriovenous malformations by the deposition of liquid embolic agents, particularly cyanoacrylates, requires judgment, technical expertise, and experience. Even though the first deposition of cyanoacrylate in human brain arteries occurred more than 25 years ago, the relative rarity of the disease and the high risk for complications has kept this procedure from being universally applied. Physicians are fortunate that, within the past year, new and better catheters have become available, and with the promise of approved cyanoacrylate devices that are now being evaluated, the future looks bright. This article reviews the history, chemistry, and uses of cyanoacrylate.