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Biomedical subjects

N R Dunnick

Publications and source records attributed to N R Dunnick.

At least 127 records · Page 7Linked to original sources
PubMed1986

The effect of ultrasonic disintegration on the outcome of percutaneous nephrolithotripsy.

Concern has been expressed regarding the use of ultrasonic lithotripsy in the percutaneous treatment of renal calculi with the suggestion that high rates of retained stones may be experienced. Evaluation of 89 patients with stones confined to the renal pelvis treated both with and without ultrasonic lithotripsy were evaluated with regard to stone size, retained fragments, stone composition and previous renal surgery. It is felt that it is not the use of ultrasonic lithotripsy that leads to longer hospitalization and retained fragments, but rather the size of the renal calculi and the complexity of arrangement.

Evaluation Studies as Topic↗
PubMed1986

A trial of combination chemotherapy followed by hormonal therapy for previously untreated metastatic carcinoma of the prostate.

We administered combination chemotherapy with cyclophosphamide, doxorubicin, and cisplatin to 25 previously untreated patients with metastatic prostate cancer in order to assess the efficacy of chemotherapy before any hormonal manipulation. Hormonal therapy was administered only after progression of disease to chemotherapy. All 25 patients were followed until time of death and all were able to receive hormonal therapy. We did not find substantially improved response rates when combination chemotherapy was applied before endocrine treatment since the 33% objective response rate to chemotherapy was only minimally higher than the response in our patients who had failed hormonal therapy and then received identical or similar chemotherapy. Furthermore, the introduction of intensive combination chemotherapy before hormonal therapy in our study did not result in any striking improvement in overall survival compared with patients who received initial hormonal therapy in many other studies. Responses to chemotherapy were not attributable to suppression of serum testosterone since all 12 patients with partial response (PR) or stable disease (SD) and four of seven patients with no response (NR) had normal testosterone levels at the time of response assessment. The initial use of chemotherapy did not adversely affect the expected high percentage of objective responses (68%) to subsequent hormonal manipulation. The frequency, duration, and quality of responses to hormonal therapy exceeded the responses to chemotherapy. The disappointing responses to chemotherapy reflect the very modest efficacy of even aggressively delivered cytotoxic agents.

Adenocarcinoma↗
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↗
PubMed1986

Timing of chest film follow-up after transthoracic needle aspiration.

Transthoracic needle aspiration of pulmonary lesions is an extremely common procedure. Pneumothorax, the most common complication, is potentially life threatening. In an effort to determine the optimum time for obtaining chest radiographs to detect pneumothorax, all cases of pneumothorax that occurred after transthoracic needle aspiration between 1981 and 1984 were reviewed. During this period, 673 transthoracic-needle-aspiration procedures were performed. Pneumothorax occurred in 160 patients (23.8%), and 78 (11.5%) of these required a chest tube or aspiration. Of the total number of pneumothoraces, 142 (89%) were detected immediately, 15 (9%) were first seen after 1 hr, and only 3 (2%) were first seen on the 4-hr radiograph. Of the pneumothoraces requiring intervention, 69 (88%) were detected immediately while the remainder were first picked up after 1 hr. There were no significant pneumothoraces detected after the 1-hr radiograph. Immediate fluoroscopy and a routine chest radiograph 1-hour postprocedure are recommended. For outpatients 1-hr and 4-hr follow-up radiographs should be taken.

Biopsy, Needle↗
PubMed1986

CT evaluation of retroperitoneal hemorrhage associated with femoral arteriography.

CT was used to assess retroperitoneal hemorrhagic complications temporally related to femoral artery catheterization in eight patients. In six patients with retroperitoneal hemorrhage caused by an angiographic complication, CT showed a high-density soft-tissue mass originating at the inguinal vessels and extending into the ipsilateral retroperitoneal spaces. In the other two patients, CT not only excluded significant bleeding from the catheterized vessel but determined an alternative diagnosis (hematoma secondary to anticoagulation and pneumatosis intestinalis due to ischemic bowel). CT findings prompted surgery in three patients.

Adolescent↗
PubMed1986

Digital indirect portography.

Thirty-eight patients underwent digital indirect portography with arterial injections of dilute contrast medium. The portal system was seen in 37 patients. Compared with conventional portography, the technique offers many advantages, including increased sensitivity and earlier visualization of the portal venous system, lower contrast loads, and lack of need for vasodilators. Digital indirect portography is an excellent method for evaluating the portal venous system.

Adolescent↗
PubMed1985

Technique to facilitate percutaneous nephrostomy in non-obstructed kidneys.

A technique for performing antegrade pyelography during nephrotomy is described--puncture with a 21-gauge, 20-cm Cope needle, placement of a 0.018-inch SMG mandril "coat-hanger"-shaped guidewire, with the needle exchanged for a 3-French multi-sidehole dilator. Use of the 3-French dilator provides more security and less trauma to the renal pelvis; nephrotomy time is also curtailed. In 25 patients the technique was used successfully with 2 minor complications.

Humans↗
PubMed1985

Renal metastases of malignant gestational trophoblastic disease: the use of intravenous urography in staging.

Intravenous urography (IVU) was performed in 289 patients at the time of diagnosis of malignant gestational trophoblastic disease (GTD). Ninety-five percent of these studies were normal, and none of the urologic abnormalities detected provoked alteration of the patients' tumor-related therapy. In the detection of renal metastases, false-positive and false-negative intravenous urograms were encountered. It is concluded that IVU lacks sufficient sensitivity and specificity in the detection of renal metastatic GTD; alternate screening methods are recommended.

Evaluation Studies as Topic↗
PubMed1985

DIgital intravenous subtraction angiography for investigating renovascular hypertension: comparison with hypertensive urography.

We used digital intravenous subtraction angiography (DSA) to evaluate 105 patients with suspected renovascular hypertension. Unilateral renal artery stenoses were identified in 14 patients, two of whom had previously had contralateral nephrectomy. In addition, one of three renal transplant recipients was found to have stenosis of the nutrient artery. Bilateral renal artery stenosis was demonstrated by DSA in three patients. Of the 88 patients who had concomitant minute sequence (hypertensive) urography (HIVP) delayed excretion suggested a renal artery lesion in only 8 patients. In the group of 88 patients, HIVP was able to detect renal artery stenosis in only 50% (eight of the 16) of patients whose stenosis was detected by DSA. When the patients with a single kidney are excluded, HIVP showed 62% (eight of 13) of the lesions detected by DSA. There were no significant complications in the patients examined by either modality. DSA has replaced HIVP as the screening examination for renovascular causes of hypertension in our institution.

Adolescent↗
PubMed1985

Tenckhoff peritoneal dialysis catheters: the use of fluoroscopy in management.

Manipulation of the Tenckhoff catheter under fluoroscopic guidance is a useful procedure in patients who undergo chronic ambulatory peritoneal dialysis (CAPD). We reviewed 50 manipulations in 28 patients. There were no significant complications attributable to the procedure. Ten per cent of the manipulations were performed for visceral pain, 40% for malfunction within the first two weeks of catheter placement, and the remaining 50% for malfunction after two weeks of adequate dialysate flow. Overall, an initial success rate of 88% was recorded, and, after long term study, a durable success rate of 58% was demonstrated. Early malfunction (i.e., within the first two weeks) is a more ominous prognostic indicator than previously realized, with only 30% of these manipulations ultimately succeeding vs. 60% of manipulations in late onset catheter failure. Nevertheless, at least one attempt is warranted in manipulation of a malfunctioning Tenckhoff catheter.

Catheterization↗
PubMed1985

Complications of percutaneous nephrostolithotomy.

In 224 patients, renal stones were removed from the urinary tract using either direct extraction with a basket or forceps (59 patients), ultrasonic lithotripsy (164 patients), or infusion chemotherapy (one patient). Residual stone fragments were present more frequently in patients treated with ultrasonic lithotripsy (27%) than with direct extraction (5%). Other complications included hemorrhage (eight patients), catheter dislodgement (four patients), large amounts of urine extravasation (three patients), glycine ascites (three patients), infection (two patients), pneumothorax (one patient), and a prolonged ileus (one patient). More complications occurred among the first 50 patients than the last 50 patients, even though more difficult cases, including patients with staghorn calculi, were accepted during the latter period. Although a learning curve exists, complications can be minimized by attempting to treat more favorable cases during the initial experience.

Extravasation of Diagnostic and Therapeutic Materi↗
PubMed1985

Percutaneous transluminal angioplasty vs. surgery for renovascular hypertension.

Therapeutic results in 102 hypertensive patients were evaluated after either renal artery percutaneous transluminal angioplasty (PTA) or surgical bypass procedures for renovascular hypertension. A minimum of 6 months of follow-up was accepted to evaluate therapeutic success or failure. Renal angioplasty had a beneficial result in each of 13 patients with fibromuscular dysplasia and in 10 (83%) of 12 patients with atherosclerotic lesions that did not involve the origin of the renal artery. Although surgery was also beneficial in each of six patients with fibromuscular dysplasia, it helped only five of 10 patients with atherosclerosis of the renal artery. Angioplasty results were similar to surgical results for atherosclerotic lesions that involved the origin of the renal artery. Angioplasty was unsuccessful in two cases of neurofibromatosis because of the firm nature of the lesions, where a bypass procedure was successful in one case. Major complications were more common in surgical cases than in angioplasty. PTA is recommended for all renal artery lesions; surgery should be reserved for failed PTA or recurrent renal artery stenosis after PTA.

Adolescent↗
PubMed1985

Percutaneous approach to nephrolithiasis.

Percutaneous techniques were successful in removing stones from 101 (92%) of 110 kidneys attempted. Ultrasonic lithotripsy was used on 80 kidneys in 74 patients with stones 5-38 mm in diameter. The most common complication was incomplete disintegration with retained stone fragments. Twenty patients were treated by direct stone extraction, either by a stone basket or forceps. The average hospitalization for percutaneous stone removal of 10 days was not significantly different from that for open nephrolithotomy. However, patients undergoing percutaneous stone removal had only a 3-10 day convalescence after hospital discharge before returning to normal activity.

Adolescent↗
PubMed1985

The significance of septations in a renal cyst.

Little is known about the significance of one or more septations within a renal cyst. The records of 26 patients whose sonographic and/or CT studies showed evidence of internal septations were reviewed to assess their significance. Thirteen patients underwent surgical exploration; in 10, the final diagnoses were benign lesions, while in three there were elements of renal cell carcinoma. Criteria are suggested to distinguish benign from malignant lesions. One or more thin septations alone is probably of no clinical significance, but if there are solid elements demonstrated, further evaluation is mandatory.

Adult↗