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Biomedical subjects

N R Dunnick

Publications and source records attributed to N R Dunnick.

At least 109 records · Page 6Linked to original sources
PubMed1987

Percutaneous dilation of benign biliary strictures.

Percutaneous balloon dilation of benign biliary strictures was successful in 15 of 18 patients in whom the procedure was attempted. Successful dilation was achieved in nine of 11 patients who had biliary enteric strictures, with follow-up of 22-55 months (mean, 35.4 months) after catheter removal in seven patients. Five of six strictures in the biliary tree that developed after surgery were successfully dilated, with long-term follow-up available in two patients (58 and 42 months). A patient with an inflammatory common bile duct stricture that was successfully dilated was followed up for 18 months. Percutaneous dilation of biliary tract strictures is a promising technique with good long-term results and may be the initial treatment of choice in biliary stricture management.

Catheterization↗
PubMed1987

Benign adrenal lesions mimicking malignancy on MR imaging: report of two cases.

Two cases of nonmalignant adrenal masses with prolonged T2 relaxation time and increased adrenal/liver signal ratios are reported. These two cases, one a functioning adenoma with small areas of hemorrhage and the other tuberculosis, emphasize that increased signal intensity in an adrenal mass on T2-weighted images is not always due to malignancy or a pheochromocytoma. While the signal characteristics of an adrenal mass are useful in distinguishing malignancy or pheochromocytoma from benign adenomas, other studies (such as computed tomography for the detection of hemorrhage), clinical evaluation, and percutaneous biopsy remain useful in the investigation of an adrenal mass.

Adenocarcinoma↗
PubMed1987

Stenoses in dialysis fistulas: treatment with percutaneous angioplasty.

Percutaneous transluminal angioplasty (PTA) was performed on 30 stenotic lesions in 25 dialysis access fistulas. The fistulas were in 23 patients with a mean age of 53 years. Lesions were detected with angiography within a few days after poor flow or increased venous pressure was documented during dialysis. Twenty-two lesions were in patients with polytetrafluoroethylene graft fistulas, five were in patients with bovine carotid fistulas, and three were in patients with endogenous arteriovenous fistulas. There were 28 venous stenoses (20 at the anastomotic site and eight more proximally) and two arterial stenoses. The overall success rate was 80%, with a 6-month patency of 76% and a mean patency after PTA of 9.4 months. Among the venous lesions, the success was 100% for proximal lesions and 71% for anastomotic lesions. There were two technical failures, which required surgery for revision of the fistulas, and four self-limited hematomas. PTA is a safe and effective treatment for stenoses in dialysis fistulas, particularly for lesions remote from the anastomotic sites.

Adult↗
PubMed1987

Contrast venography of the leg: diagnostic efficacy, tolerance, and complication rates with ionic and nonionic contrast media.

A prospective, three-center study of two contrast agents for leg venography was performed to evaluate both the relative frequency of adverse effects and whether low-osmolality agents provided significant advantages for this procedure. Fifty-four patients were studied with the standard preparation (iothalamate meglumine) and 57 with a nonionic agent (iopamidol). Both were used at an iodine concentration of 200 mg/mL, and there were no differences in volume of contrast material, duration of infusion, percentage of positive studies, or overall diagnostic adequacy. Patient discomfort was less with iopamidol than with iothalamate (18% vs. 44%), although discomfort was generally mild in both groups. By objective follow-up studies, the frequency of postvenographic thrombosis was not significantly different in the two groups (8% vs. 9%). Contrast venography, then, had a low frequency of complications when either a dilute conventional or a low-osmolality agent was employed. Although the frequency of postvenographic thrombosis was low with both agents, patient discomfort was less with the low-osmolality formulation.

Clinical Trials as Topic↗
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

Percutaneous balloon dilatation of ureteral strictures.

Percutaneous balloon dilatation of ureteral strictures has not gained widespread acceptance, despite proven success with the techniques for dilating stenotic blood vessels. Thirty-one ureteral strictures (in 30 patients) that were dilated during a 42-month period were reviewed to assess the results and to determine which patients are most likely to benefit from the procedure. Eighteen (58%) of 31 strictures were successfully dilated and remained patent for at least 6 months. Thirteen (42%) of 31 strictures resulted in failed patency either immediately (two patients) or within 3 months (seven patients), 6 months (three patients), or 21 months (one patient). Fourteen (64%) of 22 strictures less than 7 months of age were successfully dilated. All dilations for strictures more than 7 months of age failed. Four strictures were of unknown age. Nine (69%) of 13 strictures located in the proximal or midureter remained patent, and three (60%) of five dilations at a ureteroileal anastomosis were successful. Neither of two strictures at a ureterocolic anastomosis was treated successfully. We conclude that percutaneous balloon dilatation is an effective treatment of ureteral strictures in some patients, especially when the strictures are less than 7 months of age.

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

Computed tomography of the abdomen and pelvis: documentation of tumor response and progression in disseminated prostate cancer.

Computed tomography of the abdomen and pelvis has been used to stage early prostatic cancer. We investigated its value in monitoring tumor response in more advanced disease. Serial computed tomography of the abdomen and pelvis was obtained along with multiple other staging tests prior to treatment and at 3- to 4-month intervals thereafter in 32 patients with stage D2 tumor treated initially with combination chemotherapy and with hormones at progression. Pretreatment lymphography with follow-up abdominal films was also performed. Initial computed tomography of the abdomen and pelvis showed evidence of node metastases in 35% of patients while lymphography was positive in 54%. Among 19 patients with tumor response and 25 with progression, the results of treatment were objectively documented by improvement or worsening, respectively, in a mean of 5.1 and 5.0 other staging tests, exclusive of computed tomography. Computed tomography of the abdomen and pelvis improved in 85% of responding patients examined. Progression was confirmed by worsening of computed tomography in 32%. Although lymphography was often abnormal prior to treatment, in our hands it was not useful in serial monitoring of tumor status. We conclude that serial computed tomography of the abdomen and pelvis, when initially positive, is a useful test to document objectively tumor response and progression in disseminated prostatic cancer.

Abdominal Neoplasms↗
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

Factors affecting the success rate of percutaneous nephrolithotripsy and the incidence of retained fragments.

The medical records of the first 210 patients treated with percutaneous nephrolithotripsy at our university medical center were reviewed. The data were analyzed in an attempt to define those factors that affect the success rate and incidence of retained fragments of these procedures. We found that stone location and extent, and to some degree stone size are the major factors affecting the success rate and incidence of retained stones. Chemical composition of the calculus, history of renal surgery and energy source used for stone removal have lesser roles.

Adolescent↗
PubMed1986

Comparison of the costs and morbidity of percutaneous and open flank procedures.

A series of 47 percutaneous procedures for renal calculi was matched by description of calculi and previous flank exploration to 47 open flank procedures for comparison of relative morbidity and cost-efficiency. A retrospective analysis of paired data demonstrated that patients undergoing percutaneous procedures experienced significantly decreased duration of anesthesia, number of transfusions, postoperative disability, and duration and cost of hospitalization. These findings support the cost-effectiveness of the percutaneous approach to removal of renal calculi.

Adult↗
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↗