The Canadian Radiological Foundation.
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Canada↗
Biomedical subjects
E L St Louis
Publications and source records attributed to E L St Louis.
Potential for inter-observer and intra-observer variability in x-ray review to establish stone-free rates after lithotripsy.
The potential for variability among observers interpreting diagnostic tests is well known but has not been well established for radiological imaging of urolithiasis. We measured the inter-observer and intra-observer variability in the reporting of plain abdominal films and tomograms from patients who had undergone extracorporeal shock wave lithotripsy (ESWL). Unlabeled copies of the plain abdominal films and tomograms for 58 patients were individually submitted to 3 different radiologists. Selected films from 25 patients were resubmitted to the same radiologists. We found differences among radiologists reporting plain abdominal films alone 52% of the time and even by the same radiologist rereading the films 24% of the time. Tomograms alone decreased the uncertainty but differences still occurred among radiologists 24% of the time and with themselves 16% of the time. When plain abdominal films and tomograms were read together there were differences among radiologists 28% of the time and with themselves 7% of the time but these were usually minor. We concluded from this study that the plain abdominal film alone was frequently difficult to interpret, resulting in uncertainty about the presence or absence of residual stone fragments. Tomograms alone or a plain abdominal film plus tomograms is superior to a plain abdominal film alone. Finally, radiological assessment with all modalities probably overestimates stone-free rates after ESWL even without consideration of the potential for reporting variability among observers.
Humans↗
Intravenous digital subtraction arteriography in the evaluation of vascular grafts.
Between 1982 and 1986 intravenous digital subtraction arteriography was used to evaluate vascular grafts in 97 patients (54 males, 43 females). Indications included recurrent symptoms, absent or diminished pulses, a drop in Doppler pressure measurements, and clinical uncertainty with respect to graft patency. Problems identified included graft stenosis, stenosis of the anastomosis or its distal vessels, false aneurysm, arteriovenous fistula and emboli. Forty-eight operations were carried out following intravenous digital subtraction arteriography, and radiographic findings were verified surgically. Twice, intravenous digital subtraction arteriography did not show significant graft findings which were discovered at surgery. Thus intravenous digital subtraction arteriography showed a sensitivity of 95.8% and specificity of 100%. Complications following intravenous digital subtraction arteriography were: two patients developed urticaria, and one superficial thrombophlebitis. There were no cases of pulmonary edema or death. In conclusion intravenous digital subtraction arteriography is very useful in the diagnosis of graft-related problems if done on a selective basis looking at graft and anastomosis site only. Intravenous digital subtraction arteriography is done on an outpatient basis, has high sensitivity and specificity, good patient acceptance, is safe, fast and is less expensive than conventional arteriography.
Adult↗
The effect of femoral arteriography on the incidence of groin contamination and postoperative infections.
A prospective study is presented on the effects of preoperative femoral arteriography on bacterial contamination and postoperative wound complications from groin incisions. Forty-four femoral reconstructive procedures (88 groin incisions) for aortoiliac disease were performed. Positive cultures occurred in 43.2% of patients and in 30.7% of the 88 incisions. There was no correlation found between the site of arteriography and positive cultures (Spearman correlation coefficient, p greater than .10). No correlation was found between the presence of hematoma due to arteriography and subsequent positive groin culture (Spearman correlation coefficient, p greater than .10). A higher incidence of positive cultures did occur for patients who had a difficult arteriographic procedure (Fisher's exact test, p = .020) or whose reconstructive procedure was greater than four hours (Fischer's exact test, p = .047). Seven patients had postoperative groin wound complications (15.9%), including three lymph leaks (6.8%) and four confirmed or suspected infections (9%). There were no graft infections. No correlation was found between the site of arteriography and the site of wound complication (Spearman correlation coefficient, p greater than .10). Neither positive culture results nor difficult arteriography nor presence of hematoma were accurate predictors of postoperative wound complications. We conclude that transfemoral arteriography does not increase the risk of complications of arterial reconstruction involving a femoral anastomosis.
Adult↗
Is tube repair of aortic aneurysm followed by aneurysmal change in the common iliac arteries?
To address the concern that tube repair of an abdominal aortic aneurysm might be followed by aneurysmal change in the common iliac arteries, 23 patients who had undergone the operation were re-examined 3 to 5 years later. Although 9 had had minimal ectasia of these arteries preoperatively, in none of the 23 was there symptomatic or radiologic evidence of aneurysmal change on follow-up. Measurements of the maximum intraluminal diameters were made by computed tomography; they indicated no significant differences between the preoperative and follow-up sizes of the common iliac arteries. The variation in time to follow-up also showed no significant correlation with change in artery diameter.
Aneurysm↗
Computed tomography and lateral ventricular asymmetry: clinical and brain structural correlates.
Asymmetry of the ventricles of the brain without an obvious cause is a common and intriguing radiologic finding. To understand this phenomenon better the authors conducted a 24-month study to compare clinical and structural manifestations of two groups of patients who had undergone head computed tomography (CT): group A comprised 249 patients with asymmetry of the lateral ventricles of the brain without space-occupying lesions, intracranial bleeding, recent infarction or trauma and group B comprised 266 patients with the above exclusion criteria but without ventricular asymmetry. The degree of ventricular asymmetry was classified as mild, moderate or severe, according to the ratio of the larger frontal horn diameter to the smaller one. The incidence of lateral ventricular asymmetry was 5.3%. The following clinical manifestations were more frequently present in group A: headaches (p = 0.002), seizures (p = 0.007) and positive human immunodeficiency virus (HIV) status (p = 0.02). Transient ischemic attacks were more prevalent in group B (p = 0.009). Independent predictors of headache were: younger age (p less than 0.001) and the degree of ventricular asymmetry (p = 0.02). Predictors of seizures were: younger age (p less than 0.001), ventricular asymmetry (p = 0.004) and the absence of septal deviation (p = 0.009). In group A, predictors of a higher degree of asymmetry were septal deviation (p less than 0.001) and older age (p = 0.008). The authors conclude that asymmetry of the lateral ventricles of the brain is a relatively common CT finding that has important clinical and brain structural correlates and deserves more attention in the field of imaging.
Adult↗
Aneurysm of the dilatation balloon catheter: an unusual complication of percutaneous nephrolithotomy.
We present herein a previously unreported complication of an aneurysm developing in a balloon dilatation catheter used to dilate a track prior to percutaneous nephrolithotomy. Direct needle puncture of the balloon was required for removal of the catheter.
Aged↗
Percutaneous transluminal angioplasty without anticoagulation.
This paper presents the results of a retrospective study of 110 percutaneous transluminal angioplasties done over a period of two years on 110 consecutive patients. Anticoagulation or antiplatelet drugs were not used during or after percutaneous transluminal angioplasty. Life-table analysis was used to calculate success rates at one and three months following the procedure. Success rates were determined using three criteria: clinical improvement, pre- and post-percutaneous transluminal angioplasty Doppler studies, and radiographic appearance. Claudication was present in 87 (79%) patients and severe ischemia in 23 (21%) patients. Sixty-eight (62%) PCTAs were done in the iliac arteries, 35 (32%) in the femoral arteries, and 7 (6%) in the popliteal artery. The majority of patients (61%) had 50%-75% arterial stenosis and only 18% had complete occlusion. Percutaneous transluminal angioplasty in the iliac arteries had the best results with cumulative success rates of 90% and 85% at one and three months, respectively. Success rates in the femoral arteries were 83% and 79% and in the popliteal artery 71% and 57% at one and three months, respectively. None of our patients required amputation. Ten patients (9.1%) suffered the following complications within 30 days of percutaneous transluminal angioplasty: death (2), thrombosis (2), perforation (3), minor hematoma (2), and false aneurysm (1). In conclusion, we have shown that percutaneous transluminal angioplasty can be performed safely and effectively without the use of anticoagulation and its associated risks.
Adult↗
Modified catheter for percutaneous gastrojejunostomy.
A catheter for gastrojejunostomy was modified to include a Cope-loop retention device in the proximal part of the catheter and multiple side holes in the distal part. The modification was made to prevent catheter dislodgment, which can lead to infusion of feeding solution into the peritoneum. The catheter has been used successfully in 71 patients, and only minor complications have been reported.
Adult↗
Nonoperative management of complications of percutaneous renal nephrostomy.
Between 1984 and 1986 at the Wellesley Hospital in Toronto, 210 percutaneous renal nephrostomies were performed for drainage and 140 were done to provide access for nephrolithotomy. Less than 2% of the patients experienced complications requiring intervention and less than 0.5% required an open surgical approach for the management of procedure-related problems. Complications that were managed conservatively included splenic puncture, false aneurysm, laceration of the renal artery, arteriovenous fistula, hemorrhage requiring transfusion, pneumothorax-empyema, urinoma, septic shock and the hemolysis-hyponatremia-renal shutdown syndrome.
Adult↗
Comparison between transcutaneous oximetry and ankle-brachial pressure ratio in predicting runoff and outcome in patients who undergo aortobifemoral bypass.
In a prospective study, transcutaneous oxygen tension and ankle-brachial pressure index (ABI) were measured pre- and postoperatively in 105 symptomatic patients who underwent aortobifemoral bypass to compare the ability of these two measurements to reflect the runoff status, determined by angiography, and to predict the outcome of surgery. Postoperatively, ABI better reflected the runoff status. The difference in mean ABI for good versus poor runoff was 0.17 (p less than 0.05). The difference in mean transcutaneous oxygen tension below the knee for the two runoff categories was relatively small (6.3 mm Hg, p less than 0.05). Post-minus preoperative increases in ABI reflected the runoff status better than increases in transcutaneous oxygen tension. For good runoff, the mean ABI increase was 0.25 and for poor runoff it was only 0.14 (p less than 0.05). Runoff and transcutaneous oxygen tension were found to be the best predictors of symptomatic recurrence. Poor runoff was associated with a relative risk of 2.5 (p = 0.017) and transcutaneous oxygen pressure of less than 40 mm Hg implied a relative risk of 2.3 (p = 0.029) for symptomatic recurrence. The most important predictor of graft failure was preoperative ABI. Transcutaneous oxygen tension and the ankle-brachial pressure index appear to be valuable noninvasive techniques for vascular assessment, offering different insights and different predictions for management and prognosis of peripheral vascular disease.
Ankle↗
The role of intravenous digital subtraction angiography as an adjunct to computed tomography in the preoperative assessment of patients with abdominal aortic aneurysm.
The purpose of this article is to determine the role of intravenous digital subtraction angiography (IV-DSA) as an adjunct to computed tomography (CT) in the preoperative evaluation of patients with abdominal aortic aneurysm. Sixty-six patients underwent IV-DSA as well as CT during a 2-year period. Sixty-four of the 66 patients underwent abdominal aortic aneurysm repair. The results of the 66 patients were analyzed to assess what additional information was obtained by IV-DSA concerning aneurysm size, vascular anomalies, visceral arterial anatomy, associated aneurysmal disease, and iliofemoral and distal occlusive disease. On the basis of this study, it is suggested that IV-DSA has a limited role in the preoperative evaluation of patients with abdominal aortic aneurysm.
Aged↗
Percutaneous gastrostomy and gastro-jejunostomy.
Percutaneous gastrostomy and gastro-jejunostomy are new techniques which may be used instead of surgical or endoscopic gastrostomy to feed patients with an intact small bowel. We have successfully performed 72 gastrostomies on 67 patients who had had unsuccessful procedures and required surgery. Two patients developed peritonitis when their catheter dislodged into the peritoneal space.
Adult↗
Use of the Amplatz introducer sheath to facilitate ureteral stent placement.
In eight patients, 7-French double pigtail stents could not be passed through tight ureteric strictures. Coaxial placement using a 10F sheath from an Amplatz nephrolithotomy set allowed the stent to be passed through the sheath.
Humans↗
The role of CT and DSA in cranial sino-venous occlusion.
Twenty-three patients with a clinical and a radiological diagnosis of cranial sino-venous occlusion (CSO) were randomly assembled and selectively studied in a retrospective manner. Eleven instances were related to the presence of a meningioma and 12 were not. Patients in the meningioma group were older and had a better prognosis than the patients in the nonmeningioma group, but angiography was still necessary in all those with meningioma to diagnose CSO, whereas computed tomography (CT) was most helpful in permitting the diagnosis in the nonmeningioma group. The most frequent CT abnormality seen in this latter group was the "delta" or empty triangle sign (75% of scans), followed by cerebral edema (42%) and venous infarction (33%). One patient had a normal scan. The recent availability of intravenous digital subtraction angiography has helped confirm the diagnosis in a faster, safer and more reliable way. Careful interpretation of CT, especially in patients with CSO unrelated to meningioma, may result in decreased morbidity and mortality as a result of earlier diagnosis and treatment.
Cerebral Angiography↗
Percutaneous conversion of surgical gastrostomy to jejunostomy: indications and technique.
Should a surgical gastrostomy prove to be inappropriate it can readily be converted to a jejunostomy using standard percutaneous techniques. We have used this technique in six patients with gastro-esophageal reflux, four with gastric perforation, two with gastric outlet obstruction, two with duodenal perforations, and two patients with gastrostomy breakdown. Technical success was achieved in all and clinical success in 15 of 16.
Adult↗
Simplified technique of internal pudendal angiography in the investigation of impotence.
The authors describe a simplified method for evaluating the arterial status of the penis in patients with impotence. Internal pudendal angiography employing the "flour-bag" technique will likely become a routine procedure for angiographers.
Angiography↗
Failure in placement of trocar-mounted catheters.
Some commercially available catheters have a trocar with a small knob at the tip. If the catheter is pushed retrograde on the trocar such that the tip lies behind the knob, it may be impossible to advance it again. To avoid this problem, we suggest dilating the track to two French sizes larger than the catheter, using a larger stylet, or using a more rigid catheter.
Catheterization↗