Lymphoscintigraphic technique to image canine esophageal lymph nodes.

Current noninvasive methods of imaging esophageal lymph nodes have an accuracy, specificity, and sensitivity of 70%. Using a flexible esophagoscope, technetium-99m antimony sulfide colloid was injected in the esophageal submucosa of six dogs who then underwent nuclear scans to identify lymph-node location. The euthanized animals underwent dissection of cervical, thoracic, and abdominal lymph nodes. Student's t-test showed no statistical difference in the number of lymph nodes visualized in the neck (3.5 +/- 0.6), parietal thorax (1.2 +/- 0.4), visceral thorax (2.2 +/- 0.7), and abdomen (1.0 +/- 0.0) on premorbid nuclear scans and in the number of radiolabeled lymph nodes found in the neck (3.2 +/- 0.9), parietal thorax (1.2 +/- 0.2), visceral thorax (1.8 +/- 1.0), and abdomen (1.2 +/- 0.2) on dissection of the carcass. The positions of the lymph nodes based on the premorbid nuclear scans matched the locations of the radiolabeled lymph nodes at dissection. Dissected tissue was pathologically confirmed as lymph node. The position and number of lymph nodes in the cervical, intrathoracic, and abdominal regions on nuclear scan correlated with the position and number of lymph nodes found on anatomic dissection. This technique may have a higher sensitivity and specificity than current noninvasive techniques in the staging of esophageal lymphatic metastasis.

Power output of pericardium-lined skeletal muscle ventricles, left ventricular apex to aorta configuration: up to eight months in circulation.

OBJECTIVE: The purpose of this experiment was to evaluate the potential for a skeletal muscle ventricle connected to the circulation between the left ventricle and the aorta to provide effective, long-term cardiac assist. METHODS: Skeletal muscle ventricles were constructed from the latissimus muscle in 10 dogs. After conditioning, the skeletal muscle ventricles were connected to the left ventricle and the aorta with 2 valved conduits. The skeletal muscle ventricle was programmed to contract during diastole. RESULTS: At time of implantation, skeletal muscle ventricles stimulated at 33 Hz and in a 1:2 ratio with the heart significantly decreased left ventricular work by 56% (P <.01) and at 50 Hz by 65% (P <.01). At a 1:2 ratio, the power output of the skeletal muscle ventricles was 59% of left ventricular power output at 33 Hz (P <. 01) and 93% at 50 Hz (P <.01). Animals survived 7, 11, 16, 17, 72, 99, 115, 214, and 249 days. Three deaths were directly related to the skeletal muscle ventricle. One animal is alive at 228 days. In the animal that survived 249 days, skeletal muscle ventricle power output at 8 months with a 33 Hz stimulation frequency and a 1:2 contraction ratio was 57% of left ventricular power output and 82% at 50 Hz. At a 1:1 ratio, skeletal muscle ventricle power output was 97% and 173% of the left ventricle at 33 and 50 Hz, respectively. CONCLUSIONS: Left ventricular assist with a skeletal muscle ventricle connected between the left ventricle and the aorta is the most hemodynamically effective configuration we have tested and can maintain significant power output up to 8 months.

An unusual cause of hemoptysis.

Xanthogranulomatous pyelonephritis is a renal inflammatory process associated with chronic obstruction and renal calculi. A patient with xanthogranulomatous pyelonephritis presented with the acute onset of hemoptysis and a lung mass. At thoracotomy the mass was resected and found to be a renal calculus embedded within inflammatory tissue.

Transthoracic pacemaker lead insertion via the right atrium.

This case reports a right mediastinotomy approach to place DDD pacemaker leads in a patient without venous access in whom an epicardial lead was malfunctioning.

Chronic changes of end-systolic pressure-volume relationship after regional myocardial infarction.

The chronic changes of the end-systolic pressure-volume relationship (ESPVR) after regional myocardial infarction were evaluated in a sheep model. Pressure-volume area (PVA) obtained from the pressure-volume diagram and left ventricular oxygen consumption (LVO2) were studied. The regional myocardial infarction was created by ligating distal branches of the left coronary artery. ESPVR was obtained using a conductance catheter during transient inferior vena cava occlusion. Measurements were performed at baseline (n = 13), 1 hour (n = 8), 3 months (n = 9), and 6 months (n = 4) after infarction. Ees, the slope of the ESPVR did not change at 1 hour after infarction and remained the same at 3-month and 6-month measurements (baseline 2.26 +/- 1.24 mmHg/mL, 1 hour 2.71 +/- 1.06, 3 months 3.46 +/- 1.51, 6 months 2.45 +/- 0.64, NS). Because of the ventricular dilatation, which was demonstrated as an increase in changes of end-systolic volume (Ves) correlating with the time course after infarction (y = -3.21 + 0.12x, r = 0.454, p < 0.05), V0, the volume intercept of the ESPVR increased at 1 hour after the infarction, and showed a tendency to increase at 3 months and 6 months after the infarction (baseline -18.0 +/- 22.5 mL; 1 hour -0.9 +/- 11.6; 3 months 5.4 +/- 10.9, 6 months 9.2 +/- 23.1, baseline vs 3 months p < 0.05, baseline vs 6 months p < 0.05). PVA and LVO2 were unchanged over time after infarction (PVA: baseline 2097 +/- 1526 mmHg/mL per 100 g-1; 1 hour 1771 +/- 699; 3 months 2483 +/- 1086; 6 months 1,608 +/- 1,010, NS), (LVO2: baseline 40.6 +/- 13.1 x 10(-3) mL/100 g-1 per beat-1; 1 hour 42.9 +/- 9.7; 3 months 35.0 +/- 8.6; 6 months 31.2 +/- 18.1, NS). Chronic regional infarction in the sheep model did not affect Ees over 6 months, but significantly increased V0 after the increase in the acute phase. PVA and LVO2 were not affected by this regional infarction either acutely or over 6 months.

Detection of canine allograft lung rejection by pulmonary lymphoscintigraphy.

We previously demonstrated that lymphoscintigraphy could be used to study pulmonary lymphatic flow. Radiocolloids, high-molecular-weight proteins tagged with radioactive markers, are injected percutaneously in the periphery of the lung. These molecules enter the lymph, are transported via lymphatic channels, and concentrate in the tributary hilar and mediastinal lymph nodes, where they can be visualized by nuclear scan. The goal of this study was to determine whether pulmonary lymphoscintigraphy could be used to detect allograft rejection after lung transplantation. Thirteen mongrel dogs underwent left lung allotransplantation. Cyclosporine 15 mg/kg per day and azathioprine 1 mg/kg per day were given orally for postoperative immunosuppression. Lymphoscintigraphic studies were obtained 1 week after the operation and then at weekly intervals. In five dogs (group A), immunosuppression was continued until the animal died or was put to death 6 weeks later. Lymphoscintigraphy demonstrated reestablishment of lymphatic drainage between the lung graft and the mediastinum in all the animals 2 to 4 weeks after transplantation. In eight dogs (group B), immunosuppression was discontinued after reestablishment of graft lymphatic drainage was documented by two consecutive lymphoscintigraphic studies. The dogs continued to be studied with weekly scans. In group B, lymphatic drainage from the lung graft to the mediastinum disappeared 1 to 4 weeks after immunosuppression was stopped. Rejection was diagnosed clinically and confirmed histologically with open lung biopsies and/or autopsies in all animals. This study shows that canine allograft lung rejection is associated with disappearance of lymphatic drainage from lung graft to mediastinum, which can be documented by pulmonary lymphoscintigraphy, a minimally invasive technique that can be easily repeated. Pulmonary lymphoscintigraphy may be useful for early detection of lung allograft rejection.

Ketoconazole and fluconazole drug interactions.

This article reviews potential drug interactions that exist between ketoconazole or fluconazole and other drugs. English-language data sources included human subjects' computerized databases and published indexes. Case reports and studies demonstrate decreased dosage requirements of cyclosporine sodium, methylprednisolone sodium succinate, and possibly anticoagulants and phenytoin after ketoconazole or fluconazole administration, suggesting hepatic enzyme inhibition. Increased dosage requirements of ketoconazole are necessary after rifampin administration, suggesting rifampin's induction of hepatic microsomal enzymes. Possibly a similar effect may occur with concomitant fluconazole and rifampin. The effect of ketoconazole administration on prednisolone sodium phosphate and theophylline warrants further study. Fluconazole, a more selective agent for fungal P-450, seems to be of less concern regarding the potential for drug interactions than ketoconazole.

Two-suture technique for pulmonary artery anastomosis in orthotopic heart transplantation.

Distortion of the pulmonary artery anastomosis due to the size mismatch between the recipient's pulmonary trunk and the donor's pulmonary artery was the cause of acute right ventricular failure after cardiac transplantation. The problem was corrected with a two-suture technique, which has been used subsequently.

Reestablishment of lymphatic drainage after canine lung transplantation.

The technique of pulmonary lymphoscintigraphy was used to evaluate pulmonary lymphatic flow and to assess reestablishment of lymphatic drainage after lung transplantation. A first group of six control dogs underwent percutaneous transthoracic injection of a radiocolloid into the periphery of the left upper and lower lobes. Radiocolloids are large molecules tagged with radioisotopes that are absorbed only through lymph and are concentrated in tributary lymph nodes. Twenty-four hours after injection the dogs underwent scintigraphic studies of the chest and upper part of the abdomen. Mediastinal lymph nodes were visualized in all animals. A second group of four dogs underwent partial reimplantation of the native left lung, with interruption of all lymphatic connections between the lung and mediastinum. Lymphoscintigraphic studies of the left lung were obtained on the third postoperative day and then weekly for 4 weeks. Three of the four dogs in this group did not have visible mediastinal nodes 3 days after the operation. Nodes were visualized in all animals at 1 week and at all following studies. A third group of five dogs were subjected to left lung allotransplantation by means of standard surgical techniques, as well as immunosuppression. The animals were studied with radiocolloid injections and lung lymphoscintigraphy at weekly intervals for 6 weeks. Mediastinal nodes were visualized for the first time 2 to 4 weeks after the operation and at every subsequent study. We conclude that lung lymphoscintigraphy is a reliable technique for the study of pulmonary lymphatic flow. This experiment demonstrates that lymphatic drainage after lung transplantation is reestablished as early as the second postoperative week.

The effect of interstitial hyperthermia on local pulmonary blood flow and lung parenchyma.

Hyperthermia has shown promise as an anticancer therapy, but its application to lung neoplasms has been limited by whole body hyperthermia complications and the intrathoracic location of lung neoplasms. Previous studies have shown that interstitial hyperthermia could be performed through a thoracotomy approach and that animals tolerated the procedure without biochemical or hematologic abnormalities. The normal lung's local blood flow pattern and parenchymal changes due to hyperthermia of various temperatures and durations were studied. The experimental protocol applied hyperthermia through interstitial electrodes at temperatures of 39 degrees, 41 degrees, 43 degrees, and 45 degrees C. Tissue blood flow was measured with radioactive microspheres at 20, 40, and 60 minutes of hyperthermia. Histologic examination was performed of biopsy specimens taken from the heated area, from 2 and 5 cm from the heated area, and from distant parenchyma. These initial studies demonstrate that interstitial hyperthermia in the normal lung does not cause a decrease in pulmonary vascular resistance, that interstitial hyperthermia in the normal lung at temperatures of 43 degrees or 45 degrees C for durations of longer than 20 minutes decreases local pulmonary blood flow, that interstitial hyperthermia causes mild vascular disruption at temperatures of 39 degrees C or greater in the heated area but does not affect adjacent or distant lung parenchyma, and that lung hyperthermia causes generalized vascular disruption with severe widening of the pulmonary interstitium and severe hemorrhage in the heated areas when temperatures of 43 degrees or 45 degrees C are applied. Because interstitial hyperthermia affected only local lung damage, it may be applicable in the treatment of localized lung tumors.

Pharmacokinetics and toxicity of isolated perfusion of lung with doxorubicin.

The treatment of pulmonary metastases from soft tissue sarcomas with chemotherapy has an overall response rate of less than 30%, and the majority of these responses are short lived. It is postulated that increased drug delivery to the pulmonary metastases may improve the outcome of these patients. An isolated perfusion system would have the ability of delivering increased levels of drug to target tissue without the systemic toxic effect of the drug. The purpose of this study was to establish the pharmacokinetics of doxorubicin delivery, lung toxicity, and the ideal dose for clinical application in an in vivo isolated perfusion model. Our results suggest that normothermic isolated perfusion of the lung with doxorubicin using a dose level up to 6 micrograms/ml in the perfusate can be accomplished without histologic lung injury, systemic toxicity, or adverse clinical outcome. Perfusate concentration of greater than 7 micrograms/ml caused significant histologic injury and adverse clinical outcome without systemic toxicity. The technique may be utilized in selective settings to improve treatment in mesenchymal tumors metastatic to the lung.

Labetalol and MRI as initial medical and diagnostic modalities in a marfanoid patient with expanding ascending aortic aneurysm.

Marfan syndrome is a hereditable disorder of connective tissue that causes several distinct cardiovascular abnormalities, including aortic regurgitation, dissection, and aneurysm. These cardiac manifestations can be identified with echocardiography, computer tomography, and angiography. Standard treatment of an acute hypertensive crisis in Marfan syndrome uses propranolol and sodium nitroprusside. This patient with Marfan syndrome whose case is reported herein presented with chest pain, hypertensive crisis, and aortic insufficiency; labetalol was used successfully to treat the acute hypertensive crisis and magnetic resonance imaging (MRI) was used to differentiate between aortic dissection and an expanding aortic aneurysm. This report is unique in that labetalol was used to control the hypertensive crisis in Marfan syndrome and MRI was used as the initial diagnostic modality in an emergency setting.