Biomedical subjects
C Charnsangavej
Publications and source records attributed to C Charnsangavej.
Phase II trial of intracarotid BCNU and cisplatin in primary malignant brain tumors.
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.
Tracheobronchial tree: expandable metallic stents used in experimental and clinical applications. Work in progress.
An expandable stainless steel stent was formulated for use in the treatment of tracheobronchial stenosis, tracheomalacia, and airway collapse following tracheal reconstruction. The stents were placed through an endotracheal tube into the trachea and bronchi of 11 healthy dogs. The stents expanded over time, substantially increasing the diameter of the lumen. Slight migration occasionally occurred, while an inflammatory reaction was noted in each animal. The stents were successfully used in the treatment of two cancer patients to dilate a postoperative bronchial stenosis that caused pneumonia and to support a tracheal graft that collapsed with respiration. Because of the stent migration in experimental studies, designs are being tested to develop stents with greater stability. These stents may be effective in overcoming stenosis caused by scarring, extrinsic compression, and collapse of reconstructed tracheobronchial structures.
Stenosis of the vena cava: preliminary assessment of treatment with expandable metallic stents.
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.
Hepatic arterial infusion with floxuridine and cisplatin: overriding importance of antitumor effect versus degree of tumor burden as determinants of survival among patients with colorectal cancer.
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.
The carcinoid syndrome: palliation by hepatic artery embolization.
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.
Fine needle aspiration biopsy: the role of immediate cytologic assessment.
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.
Inferior vena caval stent filter.
New inferior vena caval filters for percutaneous placement were made by attaching filter wires similar to those in the bird's nest inferior vena caval filter onto expandable metallic stents. These stents formed a base on which to anchor the filter to the wall of the inferior vena cava. The stent filter can be introduced through a 12- to 13-French catheter sheath system. The system was successfully tested in 13 dogs.
Giant vascular malformation of the kidney: computed tomographic and angiographic appearances.
Two cases of giant vascular malformation of the kidney demonstrated by computed tomography and angiography are presented. The vascular malformations form completely outside the kidney. They arise from the renal parenchyma, simulating renal cyst, and present as a renal pelvic mass causing hydronephrosis. The finding of a renal mass with a markedly and uniformly contrast enhancement demonstrated by computed tomography should suggest the possibility of a vascular malformation.
Benign retroperitoneal neurilemoma without von Recklinghausen's disease: a rare occurrence.
We describe a rare case of a primary retroperitoneal neurilemoma that was confused initially on ultrasonography and computerized tomography for a renal carcinoma. These tumors vary in vascularity on arteriography, are more often solid than cystic and usually are benign in the absence of von Recklinghausen's disease. The preferred treatment is wide surgical excision.
Aspiration biopsy: use of a curved needle.
We advocate use of a curved needle to perform biopsies where underlying skeletal or visceral structures may prevent easy passage of a straight needle.
Gluteal artery occlusion: intra-arterial chemotherapy of pelvic neoplasms.
Intra-arterial chemotherapy of pelvic tumors may be complicated by coincident flow to the buttocks. Transcatheter occlusion of both the superior and inferior gluteal arteries may have a role in directing the flow of chemotherapeutic agents away from the buttocks and toward the true pelvis. The results of flow studies using technetium-99m-labeled macroaggregated human serum albumin were compared in 12 consecutive patients examined before and after transcatheter arterial occlusion, and the best results were obtained by selective occlusion of those arteries that demonstrated increased flow to the buttock on the initial study. Without the preselection of patients in whom the initial flow went mainly to the buttock, the results were inconsistent. Because of the increase in the procedure time and the occurrence of minor complications, such as local pain during or after the occlusion procedure, in all patients, proper patient selection is important.
Supraclinoid intracarotid chemotherapy using a flow-directed soft-tipped catheter.
In an attempt to avoid toxic reactions of the eye as a complication of internal carotid arterial infusion of cisplatin, carmustine, or a combination of both for the treatment of brain tumors, a new Gore-Tex/Teflon coaxial catheter system has been used for supraclinoid placement. Catheter placement was successful in 14 of 16 attempts in eight patients. Two patients experienced eye pain and conjunctivitis--a result of the chemotherapeutic agent leaking through the Gore-Tex portion of the catheter at the infusion rate of 170 ml/h. No complications were noted as long as the infusion rate was maintained at 125 ml/h or lower.
Percutaneous endovascular stents: an experimental evaluation.
Percutaneous, expanding, endovascular stents were constructed of stainless steel wire formed in a zig-zag pattern. Stents were placed for varying periods of time in the jugular vein, vena cava, and abdominal aorta in each of five adult dogs. The dilating force of the stents could be controlled by different wire size, number and angle of wire bends, and stent length. In addition, multiple stents could be placed one inside the other or one after the other, depending on the circumstance. The stents distended the vessels and increased their diameter. No flow defects, luminal narrowing, or occlusion were noted in any of the stented vessels, even after 6 months. Side branches bridged by the stents remained patent and showed no indication of narrowing. Stent wires became encased by a proliferation of the tunica intima where they contacted the vessel wall. Encasement was slower and less extensive in the abdominal aorta. No vascular erosion or clot formation was found to be associated with any of the stents.
Endovascular stent for use in aortic dissection: an in vitro experiment.
Injection of normal saline and contrast material into the walls of aortic specimens from human cadavers created a narrowing of the aortic lumen, simulating aortic dissection. Endovascular stents were applied to expand the aortic lumen. Successful dilatation of the narrowed aortic lumen was demonstrated in all six specimens.
New drugs and new delivery techniques.
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Expandable biliary endoprosthesis: an experimental study.
Expandable stents constructed of stainless-steel wire were inserted in the extrahepatic bile ducts of five animals to determine the effect of the endoprosthesis on the ductal wall. The stents were left in place 4-23 weeks, at which time the bile ducts were inspected. The bile ducts remained patent in all animals. Relatively mild reactive inflammatory changes observed in the wall of the bile ducts were more pronounced in animals with stents in place for the longest periods. A relatively small-caliber catheter (9 French) was necessary for the introduction of the stent, which acquired a much larger diameter once it was released from the catheter. This study suggests that expandable wire stents could be safely used to relieve biliary obstruction.
Infusion-embolization.
Transcatheter intra-arterial therapy for the cancer patient encompasses infusion of chemotherapy and embolization. Intra-arterial infusion of chemotherapeutic agents has been resurrected because of the availability of new drugs, combinations of drugs, and the capability of percutaneous selective catheter placement. Intra-arterial infusion has been effective in patients with carcinomas of the liver, bladder, prostate, uterus, ovary, and lung and in bone and soft tissue sarcomas, melanomas, and tumors of the brain. Embolization of the arterial supply, creating ischemia of the neoplasm, has been employed in the therapeutic management of patients with primary and secondary neoplasms of the liver, kidney, and bone. The median survival of 100 patients with neoplasms of the liver from the time of hepatic artery embolization was 11.5 months. In 100 patients with pulmonary metastases from carcinoma of the kidney, 28 experienced a response to renal artery embolization, a therapeutic delay of 4 to 7 days, nephrectomy, and Depo-Provera (medroxyprogesterone). Seven of 12 patients with giant cell tumor of the pelvis and lumbar spine responded to arterial embolization after all other therapy failed. Chemoembolization, the combination of arterial infusion of chemotherapy and embolization, can be accomplished by the use of microencapsulated agents, liposomes, and particulate emboli with drugs. This approach integrates the advantages of infusion and occlusion, and has considerable potential. Intra-arterial immunotherapy has been initiated with bacillus Calmette-Guerin (BCG) administration into renal neoplasms in patients with metastatic disease.