Pacemaker Lead Induced Inferior Vena Caval Thrombosis Leading to Portal Hypertension

Inferior vena caval thrombosis is an unusual complication of permanent pacemaker implantation. The clinical presentation due to thrombosis depends on the site of thrombus. We have described here a rare case of pacemaker lead associated thrombosis of inferior vena cava, its diagnostic work up and briefly reviewed the existing literature of this uncommon complication.     

Post-thrombotic Inferior Vena Caval Obstruction: A Review of 24 Patients

An analysis of the clinical features of 24 patients with post-thrombotic obstruction of the inferior vena cava demonstrated by phlebography showed that the possible precipitating cause was usually trivial and the onset was often associated with bed rest. The classical physical signs of bilateral leg swelling and dilated superficial abdominal wall collateral veins were often absent. In this series bilateral leg swelling was present in 42% and dilated collateral veins were present in half of the patients.A history of recurrent varicose veins and venous ulcers was common and must be taken as an indication for cavography. The presence or absence of proteinuria is no guide to the level of the caval obstruction. The value of inferior vena cavography in making an accurate diagnosis is emphasized.     

Malignant Pheochromocytoma of the Organ of Zuckerkandl Requiring Aortic and Vena Caval Reconstruction

ObjectiveTo describe a case of a malignant pheochromocytoma located in the organ of Zuckerkandl that required aortic and vena caval resection and reconstruction.MethodsWe present a case report that includes clinical, laboratory, and radiographic data as well as photographs, results from pathology, and a brief review of the literature.ResultsA 46-year-old man was referred for evaluation of a 1.4-cm left adrenal mass incidentally discovered on an abdominopelvic computed tomography (CT) scan. Subsequent laboratory evaluation revealed the following values: urine norepinephrine, 252 [μg/24 h; urine normetanephrine, 1122 [μg/24 h; urine metanephrine, 162 μg/24 h; urine epinephrine, 7 [μg/24 h; urine vanillylman-delic acid, 8 mg/24 h; and plasma metanephrine, 98 pg/ mL. Imaging characteristics of the left adrenal mass were consistent with a benign adenoma, but CT also demonstrated a hypervascular paraaortic mass. ¹²³I-metaiodo-benzylguanidine scanning with fusion CT imaging demonstrated increased radiopharmaceutical uptake within the para-aortic mass consistent with a paraganglioma in the organ of Zuckerkandl. Findings from CT angiography of the abdomen and pelvis suggested aortic involvement and vena caval thrombus. The mass was excised en bloc, including portions of the aorta, inferior vena cava, and right ureter. The aorta and vena cava were reconstructed using Dacron grafts. The remaining right ureter and kidney were removed to avoid the possibility of a urine leak from an ureteroureterostomy. Final pathologic and operative findings confirmed a malignant pheochromocytoma of the organ of Zuckerkandl with invasion into the wall of the inferior vena cava and tumor thrombus extending into the lumen.ConclusionMalignant pheochromocytoma of the organ of Zuckerkandl involving the aorta and inferior vena cava is exceedingly rare, and although surgical resection and reconstruction can be radical and aggressive, this treatment offers the only chance for cure. (Endocr Pract. 2007;13:493-497)     

Indications for treatment

Parasites produce damage to man by 1) Consumption of nutrients 2) Destruction of tissues 3) Traumatic lesions 4) Toxic action 5) Immunoallergic reactions. Humans react against parasitic attack with their natural and acquired defences. Age, race, sex, genetic endowment and nutritional status are some of the factors which influence natural immunity. Acquired cellular immunity is responsible for the state of premunition which avoids superinfection in some parasitoses. The development of an infection or of the clinical disease in an individual will depend on the interaction between the aggressive factors of the parasite and the defensive capacities of the host. In the great majority of cases an equilibrium will result: in other words, an infection. When there is a great load of parasites with great pathogenicity affecting a susceptible host, a disease will develop which can eventually result in death. Treatment should be administered on the basis of clinical, epidemiological or prophylactic considerations. In amebiasis the virulence of the races is the main parasitic factor. The difference between virulent races is quantitative and not qualitative and can be demonstrated by phagocytosis of red blood cells, “toxin” production and by inoculation into the liver of newborn hamsters. The cytotoxin has at least two components: collagenase and amebapore.The nutritional status, intestinal lumenal pH and redox potential, secretory IgA and mucus and plasma complement are some of the host factors which influence the pathogenicity of amebae. Curative treatment is indicated on intestinal or extraintestinal invasive amebiasis. Prophylactic treatment should be administered to infected food handlers and infected persons in developed countries. In toxoplasmosis, curative treatment is indicated in patients with clinical manifestations of acquired or congenital infection, in acute, sub-acute or chronic, reactivated periods. The clinical symptomatology must be correlated with serological testing which indicates “activity”. In some acquired lymph node toxoplasmosis, without general compromise, asthenia, adynamia or fever, treatment is not needed because of its good prognosis. Chronic inactivated cases, or sequelae do not require treatment. Prophylactic treatment is indicated: in: 1) Pregnant women with seroconversion to avoid congenital infection. 2) In apparently healthy children with asymptomatic congenital infection, to avoid late ocular lesions. 3) In individuals who receive immunosupressive therapy and have serological evidence of toxoplasmosis activity.In the larva migrans syndrome, treatment is indicated in patients with symptomatology oreosinophilia. The therapy may produce remission of the clinical picture or of the eosinophilia.     

Fenestration: a window of opportunity for carnivorous plants

A long-standing but controversial hypothesis assumes that carnivorous plants employ aggressive mimicry to increase their prey capture success. A possible mechanism is that pitcher plants use aggressive mimicry to deceive prey about the location of the pitcher''s exit. Specifically, species from unrelated families sport fenestration, i.e. transparent windows on the upper surfaces of pitchers which might function to mimic the exit of the pitcher. This hypothesis has not been evaluated against alternative hypotheses predicting that fenestration functions to attract insects from afar. By manipulating fenestration, we show that it does not increase the number of Drosophila flies or of two ant species entering pitchers in Sarracenia minor nor their retention time or a pitcher''s capture success. However, fenestration increased the number of Drosophila flies alighting on the pitcher compared with pitchers of the same plant without fenestration. We thus suggest that fenestration in S. minor is not an example of aggressive mimicry but rather functions in long-range attraction of prey. We highlight the need to evaluate aggressive mimicry relative to alternative concepts of plant–animal communication.