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Biomedical subjects

S Wallace

Publications and source records attributed to S Wallace.

At least 343 records · Page 19Linked to original sources
PubMed1982

Partial splenic embolization using polyvinyl alcohol foam, dextran, polystyrene, or silicone. An experimental study in dogs.

Partial splenic arterial embolization (50% reduction in flow) was evaluated in dogs using polyvinyl alcohol foam or microspheres (20-500 mu) made of dextran, polystyrene, or silicone. Dextran and polystyrene were found to be superior for several reasons: they were easier to use, did not shatter when agitated, and produced permanent, homogeneous, peripheral occlusion with only one administration. Partial embolization with dextran or polystyrene increased platelet levels within 1 week and markedly reduced splenic size with minimal if any collateral filling within 6 weeks. Microscopically, no acute infarction or necrosis was seen at 6 weeks; there was some fibrosis, but the remaining parenchyma appeared normal.

Animals↗
PubMed1982

Intra-arterial chemotherapy of malignant fibrous histiocytoma of the pelvis.

In 3 cases of malignant fibrous histiocytoma of the bony pelvis, intra-arterial chemotherapy was followed by surgical resection when possible in an attempt to control local disease without unacceptable deformity and treat undetected systemic metastases. Cis-diamminedichloroplatinum (CDDP) and a combination of intra-arterial doxorubicin, 5-(dimethyltriazeno)imidazole-4-carboxamide, and intravenous cyclophosphamide (CYADIC) were used. In 2 patients who underwent surgical resection, no viable tumor cells were found. The third patient did not respond to these or other forms of treatment. The patients treated with resection have shown no evidence of local recurrence at 24 and 9 months, respectively.

Adult↗
PubMed1982

Angiographic appearance of recurrent malignant melanoma before and after intra-arterial chemotherapy.

Intra-arterial infusion of chemotherapeutic agents (CDDP alone or combined with DTIC) was used to treat recurrent melanoma in 22 patients. In 17 cases, sequential arteriograms were obtained before and after infusion to monitor the procedure. Pre-treatment angiograms usually demonstrated rounded nodules with a homogeneous, hypervascular stain. In 3 patients, additional deep-seated lesions which were not palpable clinically were detected by angiography. Arteriograms of those patients who responded to chemotherapy revealed partial or complete disappearance of tumor stain. A 46% response rate was observed. The authors feel that angiography is valuable in pre-treatment diagnosis and post-treatment evaluation of recurrent melanoma.

Angiography↗
PubMed1982

Injury to the intima of the hepatic artery. Results of follow-up in 11 cases.

Injury to the intima of the hepatic artery is an uncommon complication of selective arteriography. Eleven such cases were followed up for less than or equal to 12 months. The status of the vessels, the experience of the angiographer, and the materials used for catheterization all affected the frequency of injury, which was manifested by a spectrum of changes including an intimal flap, aneurysm, dissection, and occlusion. No patient had significant changes in liver function. Progression to complete arterial occlusion and regression with complete healing both occurred in this series.

Adult↗
PubMed1982

Angiographic classification of hepatic arterial collaterals.

Hepatic artery collaterals in 40 patients who had had hepatic artery occlusion following peripheral or central embolization, surgical ligation, intra-arterial chemotherapy, or intimal injury from catheterization were studied. The collaterals were classified as intrahepatic or extrahepatic collaterals. Intrahepatic arterial collaterals develop in the portal triads and subcapsular area between the lobes of the liver. Extrahepatic arterial collaterals develop in the ligaments that suspend the liver in the peritoneal cavity and through the structures that are closely attached to the liver. A simplified angiographic classification of hepatic arterial collaterals is presented.

Adenoma, Bile Duct↗
PubMed1982

Experimental canine hepatic artery embolization with polyvinyl alcohol foam particles.

Segmental and complete hepatic artery embolization with Ivalon (polyvinyl alcohol) particles (0.25 to 1 mm) was performed in 12 dogs to evaluate hepatic function alterations and histopathological changes. In dogs undergoing segmental embolization, liver function alterations were minimal and the liver was normal, both grossly and microscopically, at autopsy. In dogs undergoing complete hepatic embolization, only two had significant elevation of SGOT and alkaline phosphatase levels, which normalized in 2 and 4 weeks; one of these two dogs also had an elevated bilirubin level. A focal hepatic infarct was observed both grossly and microscopically in one dog and only microscopically in four dogs. Two dogs died of pancreatic abscess due to unintentional pancreatic embolization. The study suggested that segmental embolization with Ivalon particles was well tolerated by dogs, and complete hepatic embolization resulted in hepatic function changes and focal infarction comparable with Gelfoam embolization.

Alkaline Phosphatase↗
PubMed1982

Therapeutic Ivalon embolization of hepatic tumors.

Ivalon particles were used for 80 hepatic artery embolizations in 50 patients who had either primary or metastatic hepatic neoplasms. Ten patients died within 1-5 months and the remaining 40 patients were still alive. The post-hepatic embolization syndrome was identical to that following Gelfoam embolization. Follow-up hepatic angiography in 20 patients revealed tumor response to embolization in 17 patients. Ivalon particles were easier to use and caused more peripheral and persistent occlusion than Gelfoam. The results suggest that Ivalon particles were safe and feasible for hepatic artery embolization.

Adult↗
PubMed1982

99mTc-labeled macroaggregated albumin in intrahepatic arterial chemotherapy.

One hundred eighty-four 99mTc-labeled macroaggregated albumin (99mTc-MAA) perfusion studies were carried out in 39 patients with histologically proven primary (four) and metastatic (35) hepatic neoplasms. Three different patterns of tumor perfusion were observed: (1) increased central radioactivity (33%); (2) decreased central radioactivity (33%); and (3) mixed and/or diffuse radioactivity (33%). Extrahepatic perfusion as evidenced by radioactive localization in the region of the stomach, pancreas, and small bowel was noted in 51%. Its presence was associated with a higher incidence of gastrointestinal complications (45% vs. 16%). Tumor arteriovenous shunting was demonstrated in 38%, showing localization of radiotracer activity in the lungs, and decreased as tumors decreased in size. The use of 99mTc-MAA infusion studies in intrahepatic arterial chemotherapy offers an excellent evaluation of catheter placement and tumor perfusion, in addition to helping to avoid gastrointestinal complications.

Adult↗
PubMed1982

Radiographic and angiographic changes in osteosarcoma after intraarterial chemotherapy.

Transcatheter arterial infusion has improved the preoperative control of osteosarcoma. The conventional radiographs and angiograms of osteosarcoma were evaluated in 53 patients before and after treatment. In the responders, two types of calcifications representing healing are observed: peripheral and central. The calcification is readily differentiated from that of tumor new bone. Angiography revealed a decrease in tumor vascularity and stain in responding tumors. Excellent angiographic and pathologic correlation of these changes is presented.

Angiography↗
PubMed1982

Reduction of doxorubicin cardiotoxicity by prolonged continuous intravenous infusion.

Doxorubicin (Adriamycin) was administered by continuous infusion to reduce peak plasma levels and thus lessen cardiac toxicity. Cardiotoxicity was monitored by noninvasive methods, and endomyocardial biopsy specimens were studied by electronmicroscopy. Cardiotoxicity was compared in 21 patients receiving doxorubicin intravenously over 48 or 96 hours and in 30 control patients treated by standard intravenous injection. Both groups were studied prospectively and were well matched by risk factors for doxorubicin cardiotoxicity. The median cumulative dose for those receiving continuous infusion was 600 mg/m2 body surface area (range, 360 to 1500 mg/m2) compared with 465 mg/m2 (range 290 to 680 mg/m2) in the control group (p = 0.002). Fourteen of the 30 patients in the control group showed severe morphologic changes in the biopsy specimens, precluding further doxorubicin administration, as compared with two of 21 patients receiving the drug by continuous infusion (p less than 0.02). The mean pathologic score for the infusion group, 0.9, was lower than the mean for the control group, 1.6 (p = 0.004). Antitumor activity was not compromised. Decreasing peak plasma levels of doxorubicin by continuous infusion reduces cardiotoxicity.

Adult↗
PubMed1982

Preferential coronary arterial drug delivery.

A transcatheter technique for administering drugs preferentially to the canine left coronary circulation is described. The method involves pulsed, diastolic, small-volume (0.2 ml) injections through a specially designed aortic cusp catheter. In order to evaluate preferential delivery to the coronary circulation, papaverine was administered using this technique and compared to intravenous delivery. Left circumflex and carotid arterial blood flow, as well as systemic arterial pressure, were simultaneously measured. In eight of ten animals studied, diastolic aortic cusp administration of the drug for periods of up to 30 minutes increased circumflex flow an average of 136%, increased carotid arterial flow 22%, and decreased systemic arterial pressure 18%. Intravenous delivery increased circumflex flow an average of 34%, increased carotid flow 41%, and decreased systemic arterial pressure 13%. The technique has immediate research and potential clinical application as a means of preferentially delivering diagnostic or therapeutic agents, such as thrombolytics, to the coronary circulation.

Journal Article↗
PubMed1982

Management of pelvic complications of malignant urothelial tumors with combined intra-arterial and iv chemotherapy.

Twenty-nine patients with local-regional pelvic recurrences of malignant urothelial tumors were treated with combined intra-arterial and iv chemotherapy. 5-FU (1 g/m2) was infused daily for 5 days via bilateral percutaneously placed hypogastric catheters. Doxorubicin (25 mg/m2) was infused iv on Days 1 and 2 and mitomycin (5 mg/m2) was infused iv on Days 3 and 4 of each course. Seventeen patients (58%) demonstrated an objective decrease in the size of the pelvic mass. All four patients with one of the adenocarcinoma variants of malignant urothelial tumors responded to therapy, while the three patients with squamous transformation of a transitional cell carcinoma failed to respond. The median survival of the responding patients was significantly longer (52 weeks) than that of nonresponding patients (28 weeks) (P = 0.002). Patients with initial low-volume pelvic disease demonstrated durable control of local residual tumors, with four of six patients having negative repeat cystoscopic examinations.

Adenocarcinoma↗
PubMed1982

The radiologic diagnosis and management of hepatic metastases.

The diagnosis of hepatic metastases is the responsibility of the diagnostic radiologist. In a comparison of the screening techniques, scintigraphy, sonography, and computed tomography, CT is the best single examination to determine the presence and extent of a hepatic mass. Hepatic angiography is now reserved for problem solving and in preparation for therapeutic management. Superselective catheterization is imperative and can be accomplished in 95%. Transcatheter management by hepatic artery infusion and embolization is feasible because the blood supply to hepatic metastases originates almost exclusively from the hepatic artery (90-95%), while the normal liver parenchyma has a dual supply--hepatic artery (25%) and portal vein (75%). This treatment delivered to the hepatic artery selectively effects the neoplasm. In the event of multiple hepatic (45%) arteries, occlusion of the aberrant artery with a steel coil redistributes flow through a single artery to facilitate infusion. The median survival from the time of the initiation of hepatic artery infusion for the treatment of metastatic colorectal carcinoma is 8 months and 15 months when the infusion is associated with occlusion. The median survival of 11.5 months is observed from the time of hepatic artery embolization which usually is done after failure of all other therapeutic modalities.

Angiography↗
PubMed1982

Bone metastases from renal carcinoma. The preoperative use of transcatheter arterial occlusion.

Surgical treatment of hypervascular bone lesions can result in excessive operative blood loss. We reviewed the cases of eight patients who were operated on for hypervascular bone metastases from renal carcinoma after preoperative transcatheter embolization. The embolization was successful in six of these patients and their operative blood loss averaged only 550 milliliters (range, 450 to 750 milliliters). The reasons for failure in two patients were failure to recognize and embolize all major vessels supplying the tumor in the first and the presence of too many small vessels arising directly from the superficial femoral artery to embolize safely in the second. When surgical treatment of hypervascular bone metastases is indicated, consideration should be given to preoperative arterial embolization.

Adenocarcinoma↗