Search PubMed⌕ Search

Biomedical subjects

J F Pedersen

Publications and source records attributed to J F Pedersen.

At least 55 records · Page 3Linked to original sources
PubMed1995

Pyloric size in normal infants and in infants suspected of having hypertrophic pyloric stenosis.

Pyloric muscle thickness (PMT) and pyloric diameter (PD) were determined by sonography in 92 healthy infants aged 8 to 70 days. PMT and PD measured median 2.0 mm and 10.0 mm. There was a significant correlation between the pyloric dimensions and the infant's age, p < 0.02 and p < 0.00001 for PMT and PD, respectively. In 26 infants with an initial diagnosis of hypertrophic pyloric stenosis (HPS), but with a final diagnosis of no HPS the mean figures were 2.4 and 11.0 mm, and in 21 infants with HPS, confirmed at surgery, the figures were 4.0 and 14.0. The pyloric dimensions in the 3 groups differed significantly. The larger-than-normal pyloric dimensions in the "no HPS" group suggest that some of these patients suffered from milder degrees of HPS.

Age Factors↗
PubMed1994

[Ultrasonic evaluation of peri-intestinal lymph nodes in patients with colorectal cancer].

The aim of this study was to compare the number of lymph nodes detected by sonography with the actual number and nature of the lymph nodes found on histopathological examination. Twenty colorectal specimens with carcinoma were studied. Sonography was performed with the bowel submerged in water and pericolonic lymph nodes were marked on a drawing of the specimen. After fixation, pericolonic lymph nodes were identified by palpation and their location and size were noted on a similar drawing. By comparing the sonographic and histological findings it was possible to determine which nodes had been identified by sonography. Histological examination detected 205 lymph nodes in the 20 specimens. Sixty-four of them (31%) were found by in vitro sonography (25% of the benign nodes, 56% of the malignant nodes). Preoperative endosonographic assessment (performed in 10 of the patients) generally showed fewer lymph nodes than what was subsequently found by in vitro sonography. The inability of sonography to detect more than 56% of the metastatic lymph nodes makes preoperative endosonographic assessment less valuable than hitherto believed.

Carcinoma↗
PubMed1994

Electromyography of the internal anal sphincter performed under endosonographic guidance. Description of a new method.

PURPOSE: The aim of our study was to investigate internal anal sphincter electromyographic signals. METHODS: Electromyography of the internal anal sphincter was performed with platinum wire electrodes in six healthy volunteers (three males and three females), inserted under endosonographic guidance. Platinum wire electrodes were also inserted into the external anal sphincter. Activity of both the internal and external and sphincter in a 40-second period was measured. RESULTS: Internal anal sphincter median activity was 22.1 (range, 5.5-67.6) microV. Slow-wave activity was 47 cycles/minute (range, 34-55 cycles/minute). After inflation of a rectal balloon with air until a constant relaxation of the anal canal was obtained, a decrease in internal and sphincter activity to 15.9 (1.2-31.3) microV as well as a decrease in slow-wave activity to 34 cycles/minute (range, 27-40 cycles/minute) was found. The original internal anal sphincter EMG was resumed after deflation of the rectal balloon. External anal sphincter median activity was 3.1 (range, 0.77-18.6) microV. During inflation of the rectal balloon, a reflex increase in external sphincter EMG activity was found. With the rectal balloon fully inflated a part of this increase was still present, 11.0 (1.9-24.6) microV. In some of the subjects, this increased activity was superimposed on the internal anal sphincter recordings as well. During a voluntary squeeze it was not possible to identify internal anal sphincter activity due to activity of the external anal sphincter totally overriding the internal anal sphincter signal. CONCLUSION: Precise EMG recordings from the internal anal sphincter is possible with endosonographic guidance of the electrodes, except during voluntary squeezing of the external and sphincter.

Adult↗
PubMed1994

Endosonographic assessment of the anal sphincter after surgical reconstruction.

PURPOSE: Patients with anal incontinence attributable to trauma are usually treated by sphincter reconstruction. Failures because of incomplete reconstruction may possibly be detected by anal endosonography which gives detailed information on the anal sphincter muscles. The aim of this study was to describe the endosonographic findings in patients after sphincter reconstruction. MATERIALS AND METHODS: Ten female patients who had undergone surgical sphincter reconstruction using an overlapping technique because of anal incontinence were studied with anal endosonography a median of six months after surgery. Five patients were fully continent, three were incontinent for flatus, and two patients were still incontinent for solid stool at the time of this study. Eight patients had also been studied with endosonography before surgery, and, in these patients, we compared the initial sonograms with the follow-up sonograms. The angular extent of the endosonographic defects in the external sphincter before and after reconstruction was measured in degrees and compared with the outcome of surgery. RESULTS: After reconstruction, continuity of the external anal sphincter was completely restored at all levels in four patients, one of whom still had anal incontinence. Continuity was partially restored in three patients: two were fully continent, while one patient, previously incontinent for stool, was incontinent for flatus. In three patients the continuity was restored at one level but a persisting defect was found at a different level. In two of these patients the grade of incontinence was unchanged. Three patients also had defects in the internal anal sphincter. CONCLUSION: After surgical sphincter reconstruction for anal incontinence, we found sphincteric defects in six patients, including four of five patients who still had some degree of incontinence. Thus, endosonography may be used for postoperative assessment and may explain the unsatisfactory results of surgery in some patients. We recommend that endosonography be also performed preoperatively, whereby the effect of the operation on the size of the sphincteric defect can be assessed.

Adult↗
PubMed1994

Complications of ultrasound-guided nephrostomy. A 5-year experience.

In a 5-year period (January 1987 to December 1991) a total of 285 US-guided nephrostomy procedures were performed in 159 patients. All nephrostomies were performed with a 2.3 mm one-step trochar catheter without internal fixation. The hospital case records were reviewed retrospectively, and complications were registered. The overall success rate was 92%. The catheters were maintained for a median of 17 days (range 1-150 days). Thirty-three catheters slipped out unintentionally in the first 10 days. Haematuria through the catheter for more than 3 days occurred in 14 cases. Complications occurred in 19 (6.7%) of the procedures. One uraemic patient had cardiac arrest but was resuscitated. Two patients had severe haematuria and one of them had a nephrectomy. Seven patients developed septicaemia, and 6 had perirenal bleeding or urinary leakage. Three patients developed skin infection. Ultrasound-guided nephrostomy is a gentle procedure with only few major complications, but the risk of the procedure should still be weighed against the expected benefit.

Female↗
PubMed1993

[Anal ultrasonography in anal incontinence].

Endosonography gives detailed information on the internal and external anal sphincters. The goals of this study were to evaluate findings on anal endosonography in patients with anal incontinence and to study the value of endosonography for selecting the most effective surgical treatment. Forty-eight patients with incontinence for either gas (17 patients) or faeces (31 patients) were studied. Nineteen patients had idiopathic incontinence, 29 were incontinent due to previous obstetrical or surgical trauma. Endosonography and measurement of anal canal pressures were performed in all patients, 40 had needle electromyography. The endosonograms were evaluated without knowledge of the clinical findings and correlated with the results of needle electromyography, with the anal pressures, and to the type of surgery subsequently performed. In 30 patients surgery was subsequently planned on the basis of the results of endosonography and the anophysiologic examinations. Endosonograms showed defects in 27 external sphincters, 12 of whom had internal sphincter defects also. One patient had an abnormal thinning of the external sphincter. Eight patients had defects of the internal sphincter as the only finding. Twenty-two of the patients with sonographically detected defects or thinning of the external sphincter had an EMG performed, this showed defects of the external sphincter in 18, four defects in the middle and upper anal canal had not been found. There was no correlation between the sphincteric defects found by endosonography and the anal canal pressures. Sphincter reconstruction was offered to most patients with damage to the external sphincter; patients with isolated defects in the internal sphincter or intact internal and external sphincters were offered a number of other surgical procedures.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Rectal endosonography in the evaluation of stenotic rectal tumors.

Preoperative evaluation of stenotic rectal tumors is important since they often involve adjacent organs and thus may require additional therapy. Previous reports on endosonographic staging have excluded stenotic tumors because they could not be fully visualized with the available equipment. In this study, we have evaluated the role of endosonography in staging stenotic rectal tumors, with special attention to the use of forward-looking endoprobes. Preoperative staging was performed in 28 patients with stenotic rectal tumors. Tumor extension was evaluated according to the TNM classification, and the results were compared with surgical and histopathologic findings. Endosonography accurately assessed tumor extension in two T2 tumors, 14 T3 tumors, and seven T4 tumors. Three T2 tumors were overstaged, and two T4 tumors were staged as T3. The accuracy was 82 percent. Twenty-two tumors were subject to histopathologic evaluation of lymph nodes. Lymph nodes larger than 1 cm had been seen by endosonography in eight patients, five of whom had nodal metastases. Lymph nodes smaller than 1 cm or no lymph nodes were found in 14 patients, four of whom had nodal metastases. In conclusion, full sonographic visualization of stenotic rectal tumors and thus evaluation of tumor extension can be achieved by using forward-looking endoprobes.

Adult↗
PubMed1993

Risk of sphincter damage and anal incontinence after anal dilatation for fissure-in-ano. An endosonographic study.

Follow-up was performed two to six years after anal dilatation for fissure-in-ano in 32 consecutive patients who had not undergone additional anal surgery. All patients were interviewed and asked specifically about impairment of flatus or fecal control and its possible relation to the anal dilatation. Anal dilatation was followed by minor anal incontinence in 12.5 percent of the patients. Anal endosonographic follow-up was accepted by 20 patients, and sphincteric defects were found in 13 (65 percent) of those. Two patients with anal incontinence had internal sphincter defects. Sphincteric defects were also found in 11 of the 18 continent patients who underwent sonography: internal sphincter defects in nine, external sphincter defect in one, and combined defects of both sphincter muscles in one. In conclusion, anal dilatation results in sphincter damage in more than half of patients, but few of them develop anal incontinence.

Adult↗
PubMed1993

Simple renal cyst: relations to age and arterial blood pressure.

Simple renal cysts are increasingly common with increasing age, as is elevated arterial blood pressure. We studied the natural history of simple renal cysts, and their possible association with arterial hypertension. Renal sonography was performed in an age- and sex-stratified random sample of 686 healthy volunteers aged 30-70 years. Eleven examinations were excluded for various reasons. One or more renal cysts measuring 10-47 mm were found in 35 individuals. The prevalence of simple renal cysts was 5.2%, ranging from 0% at age 30 to 9.7% at age 70. From the cross-sectional data it is estimated that the average renal cyst needs about 10 years to reach 20 mm in size. Mean arterial blood pressure increased with age, and was significantly higher in individuals with cysts (p = 0.0055). Closer analysis showed that the association was confined to and even stronger (p = 0.00066) for individuals with at least one cyst < or = 20 mm. We assume that smaller cysts are more likely to be totally intraparenchymal, and therefore more able to create an internal hydrostatic pressure and thus to compress the surrounding renal tissue.

Adult↗
PubMed1993

Kidney dimensions at sonography: correlation with age, sex, and habitus in 665 adult volunteers.

OBJECTIVE: The purpose of this study was to investigate the normal sonographic measurements of the kidney in adult volunteers. SUBJECTS AND METHODS: Length, width, and thickness of the kidney and its central echogenic area and the parenchymal thickness of the upper pole were measured in an age- and sex-stratified random sample of 665 volunteers 30, 40, 50, 60, and 70 years old. Measurements were made with the volunteers prone. Volumes of the kidney, the central echogenic area, and the renal parenchyma were calculated. Renal dimensions and renal and parenchymal volume were correlated with age, height, weight, body mass index, and total body area. In 94 subjects, renal length was measured with the volunteers supine also. RESULTS: Median renal lengths were 11.2 cm on the left side and 10.9 cm on the right side. Median renal volumes were 146 cm3 in the left kidney and 134 cm3 in the right kidney. Renal size decreased with age, almost entirely because of parenchymal reduction. Renal volume correlated best with total body area. Renal length correlated best with body height. Measurements of renal length obtained with the subjects supine were not significantly different from those obtained with the subjects prone. CONCLUSION: The most exact measurement of renal size is renal volume, which showed the strongest correlation with height, weight, and total body area. Clinically, measurement of renal length is most practical and can be done with the subject prone or supine.

Adult↗
PubMed1993

Endosonographic evaluation of patients with anal incontinence: findings and influence on surgical management.

OBJECTIVE: Endosonography using an anal probe gives detailed information about the internal and external anal sphincters. The goals of this study were to evaluate findings at anal endosonography in patients with anal incontinence and to study whether endosonography might replace needle electromyographic mapping in providing information on the external anal sphincter. Furthermore, we compared the type of sphincter damage found by endosonography with the anal canal pressures and studied the value of endosonography for selecting the most effective surgical treatment. SUBJECTS AND METHODS: Forty-eight patients with incontinence for either gas (17 patients) or feces (31 patients) were studied. Nineteen patients had idiopathic incontinence, 29 were incontinent as a result of previous obstetrical or surgical trauma. Endosonography and measurement of anal canal pressures were performed in all patients; 40 had needle electromyography. The endosonograms were evaluated without knowledge of the clinical findings, and the endosonographic findings were correlated with the results of needle electromyography, with the anal pressures, and with the type of surgery subsequently performed. In 30 patients, surgery was subsequently planned on the basis of the results of endosonography and the anophysiologic examinations. RESULTS: Endosonograms showed defects of the external sphincters in 27 patients, 12 of whom had internal sphincter defects also. One patient had an abnormal thinning of the external sphincter. Eight patients had defects of the internal sphincter as the only finding. Twenty-two of the patients with sonographically detected defects or thinning of the external sphincter had electromyography, which showed defects of the external sphincter in 18; four defects in the middle and upper anal canal were not found. The sphincteric defects found by endosonography did not correlate with the anal canal pressures. Sphincter reconstruction was offered to most patients who had damage to the external sphincter; patients with isolated defects in the internal sphincter or intact internal and external sphincters were offered a number of other surgical procedures. CONCLUSION: Endosonography can be used in place of the invasive electromyographic mapping for detecting defects of the external sphincter, and endosonography also gives additional information on the internal sphincter, which cannot be obtained by other means. No correlation between the anal pressures and the type of sphincter damage found by endosonography can be demonstrated. The main reason for performing endosonography is to detect defects in the external sphincter, for which surgical reconstruction is most likely to be done, whereas visualization of internal sphincter defects seems to have no influence on surgical management and does not lead to any specific treatment.

Adult↗
PubMed1993

Detection of pericolonic lymph nodes in patients with colorectal cancer: an in vitro and in vivo study of the efficacy of endosonography.

OBJECTIVE: Rectal endosonography is useful for the preoperative detection of perirectal lymph nodes in patients with rectal carcinoma, but some lymph nodes may be overlooked. The aim of this study was to compare the number of lymph nodes detected at sonography with the actual number and the pathology of the nodes found on examination of surgical specimens. MATERIALS AND METHODS: Colorectal specimens from 20 patients who had undergone resection of the colon (six patients) or rectum (14 patients) for carcinoma were selected for study. Sonography with 7-MHz endoprobes was performed with the bowel opened and submerged in water. The location and size of all lymph nodes that could be visualized in the pericolonic fat were marked on a drawing of the specimen. Distinction between malignant and benign nodes was not attempted. After fixation, pericolonic lymph nodes were identified by careful palpation, and their location and size were noted on a similar line drawing of the specimen. This was performed "blindly" without knowledge of the sonographic findings. By comparing the sonographic localization and size of the nodes with the histologic findings, it was possible to determine which nodes had been identified and which had been overlooked on sonograms. Preoperative endosonography had also been performed in 10 patients with rectal carcinoma, and the number of lymph nodes detected with this examination was compared with the results of the in vitro sonographic and histopathologic examinations. RESULTS: Histologic examination detected 205 lymph nodes in the 20 specimens. Sixty-four (31%) of them were seen on in vitro sonograms (25% of the benign nodes and 56% of the malignant nodes). The overall detection rates were 16% for nodes less than 5 mm in diameter, 56% for nodes between 6 and 10 mm, and 82% for lymph nodes larger than 10 mm. Preoperative rectal endosonography generally showed fewer lymph nodes (average, 1.2 nodes) than what was subsequently found with in vitro sonography (average, 2.7 nodes). CONCLUSION: Our study suggests that only approximately half of the malignant nodes in patients with colorectal carcinoma are visualized with endosonography of the surgical specimen. Even fewer nodes are visualized on preoperative in vivo examinations. The inability to detect more than 56% of metastatic lymph nodes makes preoperative endosonographic assessment less valuable than hitherto believed. This should be considered if sonographically guided biopsy of lymph nodes is considered as part of preoperative staging.

Colon↗
PubMed1993

Decreased alpha-fetoprotein in amniotic fluid and maternal serum in diabetic pregnancy.

OBJECTIVE: To determine a reference level for alpha-fetoprotein (AFP) in the amniotic fluid (AF) in pregnant women with insulin-dependent diabetes mellitus in order to suggest an explanation for the observed decrease in maternal serum AFP. METHODS: Alpha-fetoprotein was measured in AF, maternal serum, or both in the second trimester in 287 pregnant women with insulin-dependent diabetes mellitus. Retrospectively, these AFP values were correlated with glycosylated hemoglobin (HbA1C) levels, early fetal growth delay, and congenital malformations. RESULTS: The median concentration of AFAFP was 0.89 multiples of the normative median (MoM) (n = 280; 95% confidence interval [CI] 0.88-0.93 MoM); the maternal serum AFP (MSAFP) value was 0.78 MoM (n = 155; 95% CI 0.77-0.84 MoM). A statistically significant but weak positive correlation was found between HbA1C and MSAFP (r2 = 0.033, P = .03), but the correlation with AFAFP was not statistically significant. The levels of AFP did not correlate with early fetal growth delay. One neural tube defect, but none of the 11 other major malformations, was detected by AFP screening. CONCLUSIONS: A physiologic basis for the decreased AFAFP and MSAFP levels is still obscure. Screening for congenital malformations in diabetic pregnancies should include both a mid-gestation ultrasound scan and MSAFP measurement. However, routine amniocentesis does not seem to be indicated. Concentrations of AFAFP may be corrected for the observed decrease.

Amniotic Fluid↗
PubMed1993

Sonographic evaluation of renal appearance in 665 adult volunteers. Correlation with age and obesity.

The purpose of this study was to investigate the sonographic appearance of the normal adult kidney. Parenchymal echogenicity, pyramid visibility, and transverse pelvis diameter of the kidneys were prospectively determined in an age- and sex-stratified random sample of 665 volunteers 30, 40, 50, 60, and 70 years old. Furthermore, incidences of kidney stones and split sinus echo were determined. The relation between obesity and above-mentioned parameters was evaluated. In the 30-year-old age group the right kidney was isoechoic as compared to the liver in 1/3, and had clearly or faintly visible pyramids in 2/3 of the cases. These rates decreased gradually with increasing age. Transverse diameter of renal pelvis > or = 10 mm was observed in 13% of participants. Renal stones were observed in 2.1%. The incidence of split sinus echo was 3.6%. Obese participants showed lower incidences of isoechogenicity, pyramid visibility, pelvic ectasia, and split sinus echo. Isoechoic parenchyma, clearly visible pyramids, and transverse pelvis diameter > or = 10 mm are not uncommon sonographic findings in normal adult kidneys and should not be used as indicators of renal pathology.

Adult↗
PubMed1993

Anal endosonographic findings in patients with obstructed defecation.

Anal endosonography, including measurements of anal sphincter size, was performed in 16 patients with obstructed defecation. The findings were compared with those at defecography and anal manometry. Patients with rectocele and intussusception had a normal endosonographic appearance. One patient with puborectalic spasm had normal sonography. There was no correlation between sphincter size and anal manometry. The external sphincter muscle was thicker and the cross-sectional area larger in patients with obstructed defecation than in healthy controls (p < 0.05). Two patients with sphincter spasm and impaired rectal emptying at defecography had clearly thickened internal sphincters which may be the cause of their defecatory disorder. Three patients with previous anal dilatation or hemorrhoidectomy had sphincteric defects. Anal endosonography may be considered in patients with obstructed defecation to identify patients with internal sphincter hypertrophy.

Adult↗
PubMed1992

Anal endosonographic findings in the follow-up of primarily sutured sphincteric ruptures.

Twenty-four women with primary suture of an obstetric tear of the anal sphincter were examined with anal endosonography a median of 12 (range 3-18) months after delivery. Endosonography was normal in ten patients, of whom one was incontinent. The examination showed a defect in the external anal sphincter in 13 patients; six of these were incontinent, two of whom had normal findings on palpation. An isolated internal sphincter defect was found in a continent patient. Since anal endosonography causes no more discomfort than digital examination, it may be useful to identify patients who would benefit from surgical reconstruction of the anal sphincter.

Adult↗