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Biomedical subjects

R H Cohan

Publications and source records attributed to R H Cohan.

At least 73 records · Page 4Linked to original sources
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

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

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

Striated intramural gallbladder lucencies on US studies: predictors of acute cholecystitis.

Ultrasound scans of 51 consecutive patients with gallbladder wall thickening were reviewed, and specific sonographic features were correlated with surgical and clinical follow-up. Two patterns of thickening were identified as specific indicators of the presence or absence of acute cholecystitis. "Striated" wall thickening, consisting of several alternating, irregular, discontinuous, lucent and echogenic bands, was seen in eight of 13 patients (62%) with acute cholecystitis. This pattern was not encountered in any of the patients who did not have acute cholecystitis. Conversely, "three-layer" thickening, consisting of a single circumferential lucent zone between two relatively uniform echogenic layers, was seen in only one of 13 patients (8%) with acute cholecystitis but in 11 of 38 patients (29%) with other diagnoses. Other abnormalities, including the presence of intramural echogenic foci and wall irregularities, were more frequently seen in patients with acute cholecystitis but were not as helpful. Use of these features may suggest or help exclude a diagnosis of acute cholecystitis in those patients in whom the cause of gallbladder wall thickening is otherwise not apparent.

Acute Disease↗
PubMed1987

Pulmonary angiography with iopamidol: patient comfort, image quality, and hemodynamics.

The choice of a contrast agent for pulmonary angiography has important implications for patient comfort, image quality, and perhaps the safety of the procedure, particularly for "high-risk" patients. In a prospective study the nonionic, low-osmolality agent iopamidol eliminated the problem of image degradation due to coughing, and patients showed excellent tolerance for it. However, pressure measurements obtained within 3-5 minutes of injection of iopamidol and diatrizoate sodium meglumine 76% showed no significant difference in the hemodynamic effects of the two contrast agents, either for normotensive or for pulmonary hypertensive patients. Contrary to a common presumption, pulmonary hypertension by itself did not appear to increase the risk of pulmonary angiography. The theoretic presumption of greater hemodynamic stability with low-osmolality contrast agents was not clinically evident in this trial with iopamidol. At present, enhanced patient comfort and improved image quality remain the only confirmed bases for choosing this contrast agent for pulmonary angiography.

Adult↗
PubMed1987

Renal adenocarcinoma: CT staging of 100 tumors.

The preoperative CT scans of 100 pathologically proven renal adenocarcinomas were retrospectively reviewed to assess the accuracy of CT for staging the tumor. Regardless of tumor stage, perinephric extension was assessed with a sensitivity of 46% and a specificity of 98%. The sensitivity of CT in detecting venous invasion (either venous enlargement or thrombus) was 78%, with a specificity of 96%. For detection of metastatic adenopathy, CT had a sensitivity of 83% and specificity of 88%. Adjacent organ invasion was correctly identified in 60% of patients, with a specificity of 100%. Overall, CT correctly staged 91% of patients. If errors associated with perinephric invasion were excluded, CT staging accuracy improved to 96%. CT is useful in staging renal adenocarcinoma. If the renal vein is not well seen, angiography or sonography may be necessary to determine the presence of venous tumor extension.

Adult↗
PubMed1987

Lumbar hernia: diagnosis by CT.

Lumbar hernias occur in the region of the flank bounded by the 12th rib, the iliac crest, and the erector spinae and external oblique muscles. We present the CT findings of seven lumbar hernias: six traumatic (four secondary to postoperative flank incisions, one secondary to an iliac bone-graft donor site, one secondary to nonunion of an iliac fracture) and one spontaneous. Because CT portrays the anatomic relationships in this region so well, it may be the only radiographic procedure necessary to make the diagnosis of a lumbar hernia. Furthermore, it can be helpful in the assessment of symptomatic patients after flank incision, to differentiate postincisional muscular weakness and intercostal neuralgia from a lumbar hernia.

Adult↗
PubMed1987

Transthoracic needle aspiration: use of a small chest tube to treat pneumothorax.

The primary complication of transthoracic needle aspiration is pneumothorax. The efficacy and safety of using a small chest tube to treat this complication were examined by reviewing the records of 876 patients who underwent transthoracic needle aspirations between January 1981 and February 1986. Among these patients, 212 (24%) sustained a pneumothorax, and 92 (11%) required placement of a small 9-French chest tube attached to a flutter-type (Heimlich) valve. Duration of chest-tube drainage ranged between 24 hr and 3 weeks (mean, 2.2 days). Complete resolution of the pneumothorax and subsequent removal of the chest tube after 24 hr of drainage occurred in 38 (41%) of the 92 patients. Twenty-nine (32%) required 48 hr of drainage, and nine (10%) required 3 days. The remaining 16 (17%) required longer periods of drainage ranging from 4 days to 3 weeks. The tubes of six of this last group of patients were attached to a suction apparatus, and three of these patients eventually had a 28-French chest tube placed surgically. No significant complications occurred. The use of a small chest tube for treatment of pneumothorax after transthoracic needle aspiration is easy, safe, and efficacious.

Biopsy, Needle↗
PubMed1986

Ultrasonically guided percutaneous transhepatic transcholecystocholangiography in the nondilated biliary tree.

Five patients with CT or ultrasound-proven nondilated intrahepatic biliary radicles underwent ultrasound-guided percutaneous transhepatic transcholecystocholangiography (PTHTCC) for visualization of the biliary tree following failed endoscopic retrograde cholangiography. In no instance were more than 2 passes of a 22-gauge needle necessary to enter the gallbladder. Visualization of the biliary tree was excellent in all cases, and there were no complications. Therefore, PTHTCC is a safe and reliable method of visualizing the nondilated biliary tree.

Adult↗
PubMed1986

Fine needle aspiration biopsy in malignant obstructive jaundice.

Percutaneous cytodiagnosis of malignancy in patients with biliary tract obstruction is often useful in planning subsequent therapy. Of 121 patients presenting for percutaneous transhepatic cholangiography and biliary drainage, 45 had fine needle aspiration biopsies. Forty-one patients had malignant obstruction of the biliary tree, while benign disease was present in 4 patients. Neoplasia was diagnosed in 12 of 13 patients with bile duct carcinoma, 16 of 22 patients with pancreatic cancer, and 3 of 6 patients with other malignancies. Radiologic biopsy sensitivity was only slightly inferior to surgical biopsy sensitivity in the same patient population. A scheme for biliary cytodiagnosis is presented, which uses a percutaneous approach for patients with suspected pancreatic carcinoma and a transcatheter approach for patients with suspected bile duct carcinoma. The utility of this procedure and the low complication rate are stressed.

Bile Duct Neoplasms↗
PubMed1986

Infectious complications of percutaneous biliary drainage.

The infectious complications of percutaneous biliary drainage were reviewed in 132 patients with obstructive jaundice. Cholangitic or septic episodes occurred more frequently in patients with malignant (54%) than in those with benign (22%) disease, and frequently were not related to catheter insertions or manipulations. The frequency and mechanisms of bacterial colonization of bile and blood in patients with obstructive jaundice before and after biliary drainage are reviewed. The significant morbidity and mortality related to postdrainage infectious episodes is stressed, and the efficacy of antibiotic prophylaxis is discussed. The significant risks and complications of percutaneous biliary drainage must be considered prior to catheter placement, particularly in the most debilitated patients.

Bacterial Infections↗
PubMed1986

Retroperitoneal fibrosis: use of CT in distinguishing among possible causes.

Retroperitoneal fibrosis (RF) often presents with characteristic clinical and urographic findings that suggest the diagnosis. However, malignant adenopathy may mimic this appearance. CT examinations of 10 patients with medial deviation of the ureters suggesting retroperitoneal fibrosis were reviewed. Six had idiopathic RF, two had perianeurysmal fibrosis, and two had malignant retroperitoneal adenopathy. The CT findings in idiopathic RF included a homogeneous mass enveloping the ureters, aorta, and inferior vena cava. The aortic aneurysm was easily seen in both patients with perianeurysmal fibrosis. In one of the two patients with malignant retroperitoneal adenopathy, the CT findings mimicked idiopathic RF. In the other patient, the nodes involved with metastatic melanoma caused significant anterior displacement of the aorta and inferior vena cava. This marked anterior displacement of the great vessels is not seen in idiopathic RF, and may be useful in differentiating these entities.

Adult↗