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Biomedical subjects
Publications and source records attributed to S Wallace.
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We assessed the efficacy of local fibrinolytic therapy in 35 axillary-subclavian vein thromboses (SVT) that occurred in cancer patients with percutaneous central venous catheters (CVC). These catheters were indwelling for a median of 1 month (range, one day to 10 months) before thrombosis developed. Urokinase was administered at a dose of 500 to 2,000 U/kg/h. Complete lysis occurred in 25 of 30 thrombi that were directly infused, after a median of four days. Complete lysis occurred in one of 12 thrombi that could not be directly infused with urokinase and in two of six with associated phlebitis. Eighty-one percent of the thrombi that were symptomatic for less than 1 week before treatment resolved, compared with 56% present for longer than 1 week. Sixteen patients who had complete (12) or partial (four) thrombolysis did not have their CVCs removed. All four patients with partial thrombolysis had recurrent thrombosis at a median of eight days (range, one to 90). Only two patients who had complete thrombolysis had recurrent thrombosis, at 8 and 16 months. Only minor hemorrhagic toxicity was seen.
Salt use in airline meal service was studied through observation of returned meal trays of 932 passengers. Observation and weighing of salt packets on returned trays revealed that 64% of passengers did not salt their airline dinner, while 6% used the entire salt packet, 0.92 gm NaCl (362 mg Na). Average discretionary salt use among the 234 passengers (25%) who added salt was 0.57 gm NaCl (232 mg Na). Estimates of total sodium in the four airline dinners averaged 2.0 gm NaCl (786 mg Na). Laboratory assays of menu items produced by the airline foodservice differed 3% to 19% from estimated values. Sodium content of the four airline dinner menus was similar and did not affect salt use. Discretionary salt use was related to the total amount of entrée consumed but was not affected by the amount of salad consumed. It is postulated that salt use in the "captive" airline situation is predicated on consistent, habitual practices. Lowering sodium consumption in this setting may require alteration in both food preparation methods and quantity of salt presented in the packets.
Patients with ocular melanoma have a high incidence of hepatic metastases, which primarily determine their length of survival. In an attempt to control the neoplastic disease in the liver, embolization of the hepatic artery with a combination of polyvinyl sponge (Ivalon) and a suspension of cisplatin was performed in two patients with hepatic metastases from ocular melanoma. Dramatic regression of the hepatic metastases, lasting 19 and six months, occurred in these two patients after one or two such treatments. Our preliminary, albeit successful, experience with this therapeutic approach suggests that it may offer relatively prolonged periods of remission and warrants further investigation.
To simulate the intra-arterial infusion of chemotherapy, ink was infused at a steady rate through a vascular catheter inserted in a transparent tube carrying water at a rate similar to that of arterial blood. The ink ran in one or two discrete streams for 10 to 15 cm before mixing with the water, and there were substantial differences in the concentrations of ink in the water collected from side holes made at various distances from the catheter tip. If the ink was delivered in short pulses, however, it mixed with the water 2 to 3 cm beyond the catheter tip, and the samples collected from the side holes showed similar concentrations of ink. A similar situation may be encountered when chemotherapeutic agents are infused into patients. Therefore, pulsation may produce a more homogeneous drug distribution in the infused tissue. The in vitro data was substantiated in patients by the following: (1) the intra-arterial administration of technetium 99m(99mTc)labeled macroaggregated albumin (MAA) by both steady and pulsed infusions; and (2) changes in the severity of inflammatory skin reactions frequently associated with intra-arterial chemotherapy of the extremities. Improved isotope distribution was noted in 19.3% of the liver and 40% of the extremity studies. Reduced skin reactions were observed in approximately 90% of the extremities receiving pulsed chemotherapeutic infusions.
Pharmacokinetics studies were performed in ten patients who received VP-16 by intracarotid infusion at 100-300 mg/m2. VP-16 was analyzed by high-pressure liquid chromatography. ESTRIP and NONLIN were used to characterize VP-16 pharmacokinetics. VP-16 disappeared biphasically, with a t1/2 beta of 6.1 +/- 1.4 h; the total clearance was 26.8 +/- 2.8 ml/min/m2, and the Vss was 8.8 +/- 1.6 l/m2. The pharmacokinetics was not significantly different after administration by the IV route. However, at a lower dosage, less than 140 mg/m2, the half-life appears to be shorter. This may or may not be significant, since VP-16 pharmacokinetics is quite variable and the number of patients studied is relatively small. Overall, the brain and brain tumor do not appear to have any first-pass effect on VP-16 pharmacokinetics.
A coaxial infusion catheter of 3 Fr Teflon and Gore-Tex was developed to facilitate superselective catheterization of cerebral arteries for the delivery of therapeutic agents. The catheter, technique for use, and preliminary results are described.
Intracarotid BCNU (100 mg/m2) and cisplatin (60 mg/m2) were administered to 36 patients with malignant brain tumors recurrent or progressive after cranial irradiation. Courses of therapy were repeated at 4-6 week intervals. Of 23 evaluable patients with recurrent glioma, 9 (39%) had tumor regression by CT scan and 3 had stable disease. The median time to tumor progression for responding patients was 37 weeks. For all patients with primary tumors it was 14 weeks. Six of 9 patients with no prior chemotherapy had a response and 1 had stable disease. Of 14 patients who had received prior chemotherapy, 3 had a response and 2 had stable disease. Survival ranged from 9 weeks to 95+ weeks (median 34 weeks) from start of therapy. Six of 23 patients with primary tumors are alive 1 year or more following therapy. Four of 11 patients with brain metastases had a response and 2 had stable disease. Major neurologic toxicity of intracarotid BCNU and cisplatin appeared cumulative and consisted of reversible hemiparesis in 3% of 118 courses, TIA in 1%, expressive aphasia in 9%, lethargy in 3%, seizures in 12%, and reversible confusion in 1%. Retinal toxicity consisted of mild blurring of vision in 4 patients and ipsilateral blindness in 5 patients. Three of 22 patients who had received supraophthalmic infusion later developed evidence of leukoencephalopathy. Intracarotid BCNU and cisplatin appears to have modest increase in activity over intracarotid cisplatin alone (Cancer 54:794, 1984), however, neurologic and retinal toxicity may also be increased.
To test the ability of Gianturco expandable metallic stents to dilate and maintain patency in stenotic venae cavae, stenosis of the inferior vena cava was created in seven mongrel dogs by the percutaneous injection of absolute ethanol into the paravascular retroperitoneal space. Gianturco stents, placed across the stenotic segment, resulted in successful dilatation with improved hemodynamics in four dogs. The stents failed to dilate an occluded vena cava in one dog; in the remaining dogs, stent placement was complicated by early migration and occlusion. Gianturco stents were placed in two patients, one with superior vena cava syndrome and one with retroperitoneal fibrosis that obstructed the inferior vena cava, and resulted in immediate relief of presenting symptoms. These results should be viewed cautiously, but further investigation into the clinical use of the stents is indicated, especially for patients for whom other treatments are difficult.
Microcapsules, 106 micron (range, 50-350 micron), of different capsular materials (monoglyceride, monodiglyceride, natural wax, cellulose polymer, or lactic acid polymer) with and without floxuridine (2'-deoxy-5-fluorouridine, FUDR) were intraarterially injected into dog kidneys. The drug-release characteristics of the microcapsules, as determined by analysis of renal and systemic venous blood samples over a 6-hour period, were uniphasic or multiphasic depending on the capsular material. Histologic changes of varying degrees were noted in all kidneys embolized except for those subjected to capsules of the cellulose polymer. The most striking changes were produced by the lactide polymer capsules. The potential applications of microencapsuled chemotherapeutic agents in intraarterial transcatheter treatment of cancer are discussed.
Cisplatin (CDDP) was combined with floxuridine (FUDR) and delivered into the hepatic arteries of 29 patients as induction therapy for colorectal cancer metastatic to the liver. Mitomycin C and FUDR combination was substituted after progression or when response had peaked. Chemotherapy was delivered with an Infusaid pump (Infusaid Corp; Norwood, Mass; 14 patients), Medtronic programmable drug administration device (Medtronic, Inc, Minneapolis; two patients), or percutaneously placed catheters (13 patients). Complete disappearance of liver metastases was observed in four patients and 11 additional patients had a partial remission as determined by computed tomography (CT) scan and substantiated at times by angiography, for a total response rate of 52%. Response as determined by imaging techniques coincided with a concurrent decrease in carcinoembryonic antigen (CEA) and improvement in performance status. The severity of tumor burden was correlated with the response to therapy and survival. Among those patients who responded to arterial chemotherapy, differences in disease severity did not significantly influence survival. Median survival among responders with greater than 25% liver replacement by tumor was 14 months (P = .28), compared with 28 months for those patients with less than 25% liver replacement. In contrast, differences in tumor burden significantly affected survival among patients who failed to respond to chemotherapy; median survival among nonresponding patients with greater than 25% liver replacement was 4 months, compared with 8 months for those who had less than 25% liver replacement (P = .01). The presence of minimal extrahepatic disease at the time of initiation of intraarterial treatment did not seem to have a significant detrimental effect on survival. The study suggests that hepatic tumor response to arterial administration of CDDP and FUDR and mitomycin C and FUDR is clinically significant because it overrides the effect of tumor burden on survival among patients who have colorectal cancer with liver metastases and may offer effective palliation.
Three groups of dogs, four per group, were used to examine the safety of short-term arterial flow occlusion and potential benefits of balloon and/or tourniquet occlusion-infusion techniques. In part 1, local plasma gases and pH were monitored during a 1-hr period of vascular occlusion. Tourniquet occlusion was found to significantly (p = 0.01) lower pO2. In part 2, local muscle and venous blood samples were obtained during and after a 30-min intraarterial infusion of floxuridine (FUDR). A tourniquet was added to try to eliminate collateral circulation. Local FUDR concentration was increased by 1.3 times in muscle and 19.6 times (p less than 0.01) in ipsilateral femoral vein serum when a tourniquet was added to arterial balloon occlusion-infusion. In addition, the combination of the two occlusion techniques produced a 4.1-fold reduction (p less than 0.05) in systemic venous FUDR levels during infusion when compared to balloon occlusion.
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A group of 25 patients with malignant carcinoid syndrome underwent hepatic artery embolizations to palliate the symptoms of this syndrome. Twenty-three patients could be evaluated: 20 (87%) of them responded to embolization with a median response duration of 11+ months, one (4%) did not respond, and two (9%) died of complications from the embolization. The symptomatic responses correlated with two variables: (1) a decrease in the extent of the hepatic metastases in 17 of the 18 patients who had follow-up hepatic imaging, and (2) a decrease in the urine 5-hydroxyindoleacetic acid values to a mean of 41% of pretreatment levels in the 18 patients for whom this test was available. Hepatic artery embolization provides the most effective treatment for the carcinoid syndrome and the hepatic metastases. Periodic embolizations will maintain clinical remissions for prolonged periods of time.
Fifty-two thoracic and 89 abdominal aspiration biopsy specimens assessed immediately by microscopic examination were evaluated prospectively. These biopsies were compared retrospectively with an equal number and type of biopsies that were not assessed immediately by microscopic examination. The comparison was made to determine whether the diagnostic accuracy and the complication rates of fine needle aspiration cytology would be improved by immediate microscopic assessment. The accuracy of fine needle aspiration biopsy with and without immediate cytologic assessment for the thoracic aspirates was 92% and 85%, and for the abdominal aspirates it was 74% and 81%, respectively. The complication rates with and without immediate assessment for the thoracic aspirates was 40% and 35%, and for the abdominal aspirates it was 7% and 6%, respectively. Immediate cytologic assessment did not change the accuracy or complication rates of fine needle aspiration biopsy significantly, but we believe that it provided greater educational benefits for fellows and staff in cytopathology and interventional radiology.
In a V-2 model of solitary hepatic metastasis, residual tumor was histologically identified in the treatment field in only three of 14 (21%) animals subjected to microsphere embolization of tumor arterioles plus focal (43 degrees C, 40 min) hyperthermia compared with seven of ten (70%) subjected to focal (43 degrees C, 40 min) hyperthermia alone (P less than or equal to 0.05), five of seven (71%) (P less than or equal to 0.05) treated by occlusion plus sham heating, and five of five (100%) (P less than or equal to 0.01) sham-treated controls. Prior occlusion tended to reduce the radiofrequency power required for heat up and steady-state temperature maintenance of tumors (P less than or equal to 0.09 and P less than or equal to 0.06, respectively) and reduced the cooling rate after heating compared to unoccluded tumors (P less than or equal to 0.02) but did not affect mean time to temperature, maximum and minimum temperature measured at the tumor-normal tissue interface, and animal core temperature compared with that of the hyperthermia alone treatment group. In ten other animals with hepatic V-2 tumors of comparable size subjected to focal hyperthermia plus or minus arteriolar embolization, temperatures were continuously monitored at four additional intratumor sites in a fixed geometric orientation around the heating probe. No significant differences were noted in maximum and minimum temperatures in comparably oriented probes over a 40-min heating period between the hyperthermia and the occlusion-hyperthermia treatment groups. In five other animals with solitary V-2 hepatic implants, comparable microembolization plus or minus focal tumor heating to 43 degrees C, 40 min, did not significantly reduce tumor interstitial pH compared with pretreatment values. This study reproduces previously observed synergism between arteriolar embolization and hyperthermia but suggests the mechanism may be unrelated to observable differences in intratumor pH and thermal profile and may result from other mechanisms, perhaps by mimicking the angioocclusive effects of hyperthermia itself.
Twenty-one patients with inoperable colon cancer in the pelvis were treated with intra-arterial 5-fluorouracil (5-FU) and mitomycin C, given bilaterally into the internal iliac arteries. Seventeen of the 21 patients had failed previous radiation therapy and 15 had also failed systemic intravenous chemotherapy. Eighteen of the 21 patients received intra-arterial treatments because of pelvic pain. Effect of this treatment on the pain could be evaluated in 16 patients. A measurable decrease in pain medication occurred in 8 of 16, whereas a subjective feeling of pain relief was observed in 12 of 16 patients for a mean period of 3.5 months. However, objective tumor response was considered definite only if associated with a greater than 50% decline of an elevated plasma carcinoembryonic antigen level; this was observed in 5 of 11 patients (45%). Reduction in tumor mass as measured by imaging techniques was observed in two of ten patients in whom it was evaluable. Improvement in hydronephrosis was observed in five of seven evaluable patients. Hematuria was present in 12 patients and improved in 10 of those patients. The most significant side effect of chemotherapy was perineal and gluteal skin erythema, which was observed in 36% of the patients after the first course and in 24% during the second course. This frequently escalated to cutaneous vesiculation and desquamation. This side effect was prevented by concurrent administration of steroids. Pelvic arterial infusion of 5-FU and mitomycin C can offer temporary pain relief to patients who have failed other means of therapy. Objective antitumor effects may have also resulted but were much harder to assess in this group of patients.