Perioperative external pneumatic calf compression as thromboembolism prophylaxis in gynecologic oncology: report of a randomized controlled trial.

Postoperative venous thromboembolic complications are a major problem for the gynecologic oncologist. External pneumatic calf compression (EPC), when applied intraoperatively and left on the patient's legs for 5 days postoperatively, has been previously demonstrated to significantly reduce the incidence of venous thromboembolic complications in patients undergoing surgery for pelvic malignancies. The purpose of this study is to evaluate whether a short perioperative course of EPC is also effective in preventing venous thromboembolic complications. One hundred ninety-four patients participated in a randomized controlled trial of perioperative external pneumatic calf compression. 125I-labeled fibrinogen scanning and impedance plethysmography were used as prospective surveillance methods in both groups. Venous thromboembolic complications were diagnosed in 12.4% of control group patients and in 18.6% of EPC group patients. External pneumatic calf compression when used only in the perioperative period appears to be of no benefit in reducing the incidence of postoperative venous thromboembolic complications.

Survival of parenchymal hepatocytes irradiated with 14.3 MeV neutrons.

The purpose of these experiments was to estimate the RBE of neutrons for parenchymal hepatocytes as a function of neutron dose and to determine the ability of liver cells to repair potentially lethal damage (PLD) after neutron exposure. Hepatocyte reproductive survival was used as the biological end point in these studies and hepatocyte survival was determined with an in vivo transplantation clonogenic assay system. The 14.3 MeV neutrons were generated by a D-T reaction at the University of Wisconsin's gas target neutron source. The average neutron dose rate was 20 cGy/min. The estimated survival data for neutron exposed hepatocytes were best described by a single hit-single target model (i.e., n = 1.0) with a D0 = 170 cGy. In contrast to the results obtained with 60Co, hepatocytes exposed to neutrons are unable to repair PLD. The RBE value, when the reproductive survival was estimated 30 min after radiation exposure, is independent of neutron dose and equal to 1.6 +/- 0.1. In contrast, when the reproductive survival was estimated 24 hrs after radiation exposure, the RBE was found to increase with decreasing neutron dose and equal 4.2 +/- 0.5 at 50 cGy.

Cryosurgery in the management of cervical intraepithelial neoplasia.

Cryosurgery is an outpatient modality capable of destroying cervical intraepithelial neoplasia (CIN). Among 770 patients treated with cryosurgery who had at least two follow-up Papanicolaou smears, a persistence of CIN was noted in 10%. It was more difficult to destroy CIN III disease and large lesions (more than 50% of the cervix involved), although grade appeared to be more important than size of the lesion. Many patients with a persistent lesion were retreated as outpatients; as a result, in more than 96% of the 770 patients the lesion was eradicated.

Prevention of postoperative venous thromboembolism by external pneumatic calf compression in patients with gynecologic malignancy.

One hundred seven patients undergoing major surgery for gynecologic malignancy participated in a controlled trial evaluating the effectiveness of pneumatic calf compression in the prevention of postoperative deep venous thrombosis and pulmonary embolism. External pneumatic calf compression was applied intraoperatively and for five postoperative days. All patients were prospectively screened for deep venous thrombosis with impedance plethysmography and 125I-fibrinogen leg counting. Deep venous thrombosis and/or pulmonary emboli were detected in 18 of 52 control group patients (34.6%) whereas in seven of 55 (12.7%) of those treated with external pneumatic calf compression (P less than .005). External pneumatic calf compression was most effective during the first five days postoperatively and also reduced the incidence of deep venous thrombosis in patients at highest risk. When applied during surgery and for five days postoperatively, external pneumatic calf compression significantly reduces the incidence of postoperative venous thrombosis.

Stratification of risk factors in renal cell carcinoma.

One hundred fifteen patients underwent surgical treatment of renal cell carcinoma. Survival time was analyzed by statistical regression methods in order to determine the joint significance of stage, using both the Robson and TNM classifications, histologic grade, cell type, and demographic features of the patient sample. Grade and cell type were essentially interchangeable with respect to predicting survival in patients with and without metastatic disease. The strong association between these two factors explains and supports this result. The presence of metastases dramatically altered survival. Local extent of the tumor was an important indicator of survival in the nonmetastatic group of patients, but was not a statistically significant factor in those patients presenting with widespread disease. Venous involvement was not found to be of prognostic significance in either group. Age and weight loss contributed to predicting survival in the nonmetastatic patient group in addition to the measures of disease extent already discussed. Sex and race were not significant indicators of length of survival. In the group of patients with metastatic disease, no difference in survival was observed between soft tissue and bony metastases.

Histamine and calcitonin release from medullary thyroid carcinoma.

The secretagogue effect of histamine on calcitonin secretion has been studied in 15 patients with medullary thyroid carcinoma and compared with known stimuli: glucagon and calcium in combination with pentagastrin. The effect of concomitant histamine H2-receptor blockade on these responses has been studied in the same patients. Seven patients with undetectable basal plasma calcitonin concentrations had measurable responses to calcium/pentagastrin but not to histamine or glucagon. In the remaining eight subjects, significant responses were seen to all three test substances, calcium/pentagastrin proving to be the most potent secretagogue. Establishment of H2-receptor blockade with cimetidine had no effect on basal calcitonin concentrations and did not suppress responses to histamine, calcium or pentagastrin. The variable secretagogue effect of histamine could be mediated through H1-receptors, through nonspecific vascular dilation "washing out" preformed calcitonin, or through its destruction to varying degrees by histaminase, present in most medullary thyroid tumors. Histamine is unlikely to replace calcium/pentagastrin as the most discriminative, provocative diagnostic agent in medullary thyroid carcinoma, but correlation of secretory responses with tissue histaminase concentrations and attempted blockade with differing antihistamines will further our understanding of this tumor.