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Biomedical subjects

N R Dunnick

Publications and source records attributed to N R Dunnick.

At least 91 records · Page 5Linked to original sources
PubMed1988

Comparison of intravenous digital subtraction angiography and conventional arteriography in defining renal anatomy.

Intravenous digital subtraction renal angiography (IV-DSRA) is frequently used in the preoperative evaluation of living-related (LR) kidney donors. However, the true accuracy of IV-DSRA in the donor population is difficult to assess since abnormalities of the kidney and its circulation are uncommon in this group. Therefore, we evaluated IV-DSRA in a group of patients more likely to have anomalies and abnormalities that would affect LR donor selection, donor nephrectomy, and subsequent transplantation. Hypertensive adults being evaluated for renovascular hypertension had IV-DSRA and conventional renal arteriograms, which were interpreted independently. We determined the accuracy of IV-DSRA, compared with conventional arteriography, in detecting multiple renal arteries, renal artery stenosis, fibromuscular dysplasia, and abnormal renal parenchyma. Technically unsatisfactory studies were excluded from analysis. Of 59 patients evaluated, 37 had abnormalities or anomalies. IV-DSRA failed to detect 28 of 50 findings in these 37 patients. In 21 patients with multiple renal arteries, IV-DSRA underestimated the number of main renal arteries in 8. Significant renal artery stenosis, present in 16 patients, was undetected by IV-DSRA in 3 of these patients. Mild fibromuscular dysplasia was not detected by IV-DSRA in any of the 5 patients with this condition, and abnormalities of renal parenchyma were not detected in 6 of the 8 patients with scarred or cystic kidneys. When compared with conventional renal arteriography in a hypertensive population, the IV-DSRA does not accurately detect abnormalities of the kidney and its circulation. If these data are confirmed in nonhypertensive subjects, preoperative evaluation of LR kidney donors using IV-DSRA alone may fail to detect potentially important anatomic abnormalities.

Adult↗
PubMed1988

Artificial urinary sphincters: plain radiography of malfunction and complications.

Inflatable artificial urinary sphincters provide excellent voluntary continence. Eighty-four consecutive patients underwent implantation of artificial urinary sphincters for intractable urinary incontinence; 33 patients had 58 episodes of sphincter malfunction, and eight patients had eight complications involving a functional prosthetic sphincter. Retrospective analysis was performed to determine the value of plain radiography of the pelvis in patients with sphincter malfunction or complication. The cause of malfunction in the majority of patients was a system leak and subsequent loss of hydraulic fluid (31 occurrences; 53%). Plain radiography permitted correct identification of all instances of fluid leakage in patients with opacified prostheses. Plain radiographs were of no value in examining patients with nonopacified prostheses or the complications of cuff erosion or wound infection. Due to the low cost and noninvasive nature of plain radiography of the pelvis, we conclude that it should be used as the initial diagnostic modality in patients with previously opacified but currently dysfunctional artificial urinary sphincters.

Female↗
PubMed1988

Percutaneous cholecystostomy: anatomic considerations.

In 100 consecutive patients undergoing abdominal computed tomography, the anatomic relationships among the gallbladder fundus, liver, and right hemicolon were evaluated to assess the feasibility of direct transperitoneal versus percutaneous transhepatic cholecystostomy. In only 17% of patients was there no interposition of colon or liver between the skin and the gallbladder fundus. In 13% of patients the right hemicolon lay between the gallbladder fundus and skin. In the remaining 70% of patients, the gallbladder fundus was positioned posterior to the liver margin. Thus, in 83% of patients studied, percutaneous cholecystostomy would necessitate a transhepatic approach.

Catheterization↗
PubMed1988

CT prior to second-look operation in ovarian cancer.

Second-look surgery is used in restaging patients with ovarian cancer to define sites of recurrence, plan therapy, and perform tumor debulking. We evaluated the role of CT in detecting residual or recurrent tumor in 55 patients in whom 64 abdominopelvic CT scans were obtained. Forty-eight patients underwent a second-look operation, and eight of these patients had an additional third-look operation. CT correctly identified 17 (85%) of 20 cases with residual or recurrent pelvic disease and three (75%) of four cases with bulky abdominal disease. CT failed to detect tumor in any of the five cases with minimal abdominopelvic disease and was able to detect carcinomatosis in only two (8%) of 24 cases. In four cases, CT detected pelvic disease not identified on clinical pelvic examination. On the 56 scans in 48 patients with surgical proof (280 surgical findings), CT had a sensitivity of 40% (22/55) and a specificity of 99% (224/225). In seven additional patients, second-look laparotomy was canceled because of CT findings of extensive, unresectable tumor. We conclude that CT provided valuable information regarding residual or recurrent tumor prior to second- and third-look surgery. In selective cases, CT findings obviated unnecessary surgery. However, the CT's lack of sensitivity in identifying minimal abdominopelvic disease and carcinomatosis precludes its use as a substitute for second-look surgery.

Female↗
PubMed1988

Fibromuscular dysplasia of renal arteries: comparison of intravenous digital subtraction angiography with conventional angiography.

Intravenous digital subtraction angiography (IV-DSA) was compared with conventional arteriography (CA) in 14 patients with fibromuscular dysplasia (FMD) of at least one renal artery. IV-DSA identified 29 of the 34 renal arteries detected by CA. A diagnostic quality IV-DSA examination was obtained in 23 of 29 renal arteries (78%). In adequately imaged renal arteries, IV-DSA correctly identified 12 of 20 FMD renal arteries, misdiagnosed 8 FMD renal arteries as normal and correctly identified 3 normal renal arteries. These poor results, due to poor spatial resolution and subtraction artifacts inherent in the IV-DSA system, warrant careful interpretation of negative examinations and further evaluation of high risk patients.

Angiography↗
PubMed1987

Digital intravenous subtraction angiography in the evaluation of reconstructed renal arteries.

Digital intravenous subtraction angiography (DISA) was used to evaluate 28 patients who had undergone renal artery reconstruction either as part of a renal transplant procedure or for treatment of renovascular hypertension. Satisfactory visualization of the renal artery was obtained in 26 cases, and the clinical questions were adequately answered in these cases. The findings included a variety of possible outcomes and demonstrate the adequacy of DISA as a means of evaluating the results of renal artery surgery. Technical and anatomic factors affecting the quality of the examination are discussed. The cases also illustrate the critical importance of thorough familiarity with the surgical procedures in general and of mutual discussion between surgeon and radiologist in optimizing the DISA examination in a given patient.

Adult↗
PubMed1987

Percutaneous intervention in the solitary kidney.

The solitary kidney, either after nephrectomy or on a congenital basis, may be impaired by infection, stones, obstruction, and trauma. Because of the possibility of further renal compromise by damage of the remaining nephron units, there is reluctance to utilize percutaneous techniques in cases of solitary kidney, and surgery is often used as an alternative. We report 15 cases of solitary kidney in which interventional radiologic techniques (i.e., percutaneous nephrostomy, ureteral stenting, ureteral dilatation, and stone extraction) were attempted for the preservation of renal function, either as a permanent solution or as a temporizing maneuver prior to definitive therapy. In each case, these goals were achieved and there were no complications.

Adolescent↗
PubMed1987

Results and morbidity of percutaneous nephrolithotripsy.

The medical records of the first 210 patients treated with percutaneous nephrolithotripsy at Duke University Medical Center were reviewed. Eleven patients were treated for bilateral stones for a total of 221 renal units. The procedure failed in 6 patients (2.7%). Stone fragments were retained in 55 patients (24.9%), with unplanned fragments in 41 cases (18.6%). Open surgery was subsequently performed in 4 patients (1.8%). There were no nephrectomies or deaths in our patients. Percutaneous nephrolithotripsy is a highly successful method for removal of upper tract stones and has a complication rate no higher than that of open surgical procedures.

Adolescent↗
PubMed1987

Intravenous digital subtraction angiography in the evaluation of potential renal donors.

Of 65 surgically removed donor kidneys intravenous digital subtraction angiography demonstrated accurately the number of renal arteries in 58 (89 per cent). All accessory vessels missed at digital subtraction angiography were small and their presence did not interfere with successful transplantation in those donated. Of 50 surgically removed donor kidneys examined with conventional aortography only before the routine use of intravenous digital subtraction angiography the number of renal arteries was demonstrated accurately in 46 (92 per cent). Intravenous digital subtraction angiography offers advantages over conventional aortography, including most importantly the routine performance on an outpatient basis, and decreased film cost and examination time. Although the accuracy of conventional aortography (92 per cent) in detecting the number of renal arteries is slightly greater than that for intravenous digital subtraction angiography (89 per cent), the advantages of the digital examination justify its use as the initial examination for the potential renal donor. Conventional aortography can be reserved for use in patients with equivocal or technically inadequate digital examinations.

Angiography↗
PubMed1987

Percutaneous drainage of pelvic lymphatic fluid collections in the renal transplant patient.

Seventeen renal transplant patients with pelvic lymphatic fluid collections were treated with percutaneous drainage. Eleven of 16 patients with lymphoceles (69%) were successfully managed without surgery, although seven of these patients required repeat catheter insertions, and three patients developed local infections. The patient with an ovarian cystadenoma was treated with surgery. The mean duration of catheter insertion was ten days for initial drainage and 16 days for repeat drainage. Elevated serum creatinines decreased in 14 of the patients with lymphoceles (88%), including all five patients without pelvocaliectasis, but never returned to baseline in six instances. This observation may reflect the inadequate therapy of frequently encountered concurrent renal parenchymal abnormalities (rejection, cyclosporine toxicity, acute tubular necrosis). While percutaneous management of lymphoceles is technically easy and usually ultimately effective, the interventional radiologist should be prepared for long duration of catheter insertions, repeat interventions, and variable clinical courses. Differentiation of lymphoceles from other fluid collections, such as cystic ovarian neoplasms, may be difficult.

Adult↗
PubMed1987

Pulmonary arteriography in the high-risk patient.

Pulmonary arteriography is an invasive but relatively safe diagnostic procedure. It is generally believed that the presence of pulmonary hypertension is one risk factor that increases the likelihood of a major complication. To assess the magnitude of risk, the reports on 1,434 patients who underwent pulmonary arteriography were retrospectively reviewed, and the occurrence of complications in the 388 (27%) patients with pulmonary hypertension was noted. Major complications related to contrast material injection (excluding allergic reactions) occurred in 30 (2%) of the 1,434 examinations and included two deaths from acute cor pulmonale. Six complications occurred in the 388 patients with pulmonary hypertension and/or elevated right ventricular end-diastolic pressure (RVEDP). The two deaths occurred in patients with severe pulmonary hypertension and elevated RVEDP. Most patients with severe cardiopulmonary compromise tolerated angiography well. The increased risk of studying this group of patients is modest and must be weighed against the potential therapeutic benefits to the patient.

Angiography↗