The Transcallosal Anterior Interfoniceal Approach: A Microsurgical Anatomy Study.

Objectives A plethora of surgical strategies have been described to reach deep-seated lesions situated within the third ventricle including the Rosenfeld, or transcallosal anterior interfoniceal (TAIF), approach. First introduced in 2001, it consists of a small callosotomy followed by the midline transseptal dissection of fornices to enter the roof of the third ventricle. The aim of this microsurgical anatomy study is to describe and show each stage of the surgical procedure, focusing on the possible trajectories to anatomical landmarks. Participants A total of 20 adult cadaveric specimens were used in this study. Using ×3 to ×40 magnifications, the surgical dissection was performed in a stepwise fashion, and the transcallosal anterior interforniceal approach was performed, analyzed, and described. Results In 5 specimens of 10, a cavum septum pellucidum was depicted. In 5 cases of 20 after the callosotomy ,the lateral ventricular cavities were reached. Different orientation of the microscope allowed us to define three surgical trajectories to visualize the region of interest without exposing important functional areas. Conclusion The TAIF represents a minimally invasive approach to the third ventricle; its tricky surgical steps make appropriate anatomical dissection training essential to become confident and skilled in performing this approach.

3D computational fluid dynamics of a treated vertebrobasilar giant aneurysm: a multistage analysis.

BACKGROUND AND PURPOSE: The treatment of giant aneurysms of the vertebrobasilar junction remains a challenging task in neurosurgical practice, and the reference standard therapy is still under debate. Through a detailed postmortem study, we analyzed the hemodynamic factors underlying the formation and recanalization of an aneurysm located at this particular site and its anatomic configuration. METHODS: An adult fixed cadaveric specimen with a known VBJ GA, characterized radiographically and treated with endovascular embolization, was studied. 3D computational fluid dynamic models were built based on the specific angioarchitecture of the specimen, and each step of the endovascular treatment was simulated. RESULTS: The 3D CFD study showed an area of hemodynamic stress (high wall shear stress, high static pressure, high flow velocity) at the neck region of the aneurysm, matching the site of recanalization seen during the treatment period. CONCLUSIONS: Aneurysm morphologic features, location, and patient-specific angioarchitecture are the principal factors to be considered in the management of VBJ giant aneurysms. The 3D CFD study has suggested that, in the treatment of giant aneurysms, the intra-aneurysmal environment induced by partial coil or Onyx embolization may lead to hemodynamic stress at the neck region, potentially favoring recanalization of the aneurysm.

Stereotactic biopsy aided by a computer graphics workstation: experience with 200 consecutive cases.

BACKGROUND: The advent of modern computer technology has made it possible to examine not just the target point, but the entire trajectory in planning for stereotactic biopsies. METHODS: Two hundred consecutive biopsies were performed by one surgeon, utilizing a computer graphics workstation. The target point, entry point, and complete trajectory were carefully scrutinized and adjusted to minimize potential complications. RESULTS: Pathologically abnormal tissue was obtained in 197 cases (98.5%). There was no mortality in this series. Symptomatic hemorrhages occurred in 4 cases (2%). CONCLUSIONS: Computer graphics workstations facilitate safe and effective biopsies in virtually any brain area.

Influence of middle molecules on the anemia of uremic patients.

To evaluate their toxicity at the cellular level, middle molecules from uremic serum were incubated with erythrocytes from healthy subjects and the activity of the enzyme Delta-aminolevulinic acid dehydrase (D-ALA-D) and peroxidative hemolysis were investigated. Uremic middle molecules caused a significant decrease of the D-ALA-D activity of normal erythrocytes which was not due to differences in the concentrations of Pb, Cd or Zn. The decreased enzyme activity could be restored by adding reduced glutathione (GSH; 5 mmol/L) together with the middle molecules to the assay system. Uremic middle molecules caused a significant increase of peroxidative hemolysis in normal erythrocytes. Uremic middle molecules contribute to the anemia of uremic patients by impeding hemoglobin synthesis and by increasing peroxidative hemolysis, possibly by affecting SH-groups. H2O2-producing compounds should be avoided in uremic patients.

Influence of essential amino acids and keto acids on protein metabolism and anemia of patients on intermittent hemodialysis.

Ten patients were treated with 10 g/day of essential amino acids orally; nine patients received 9.5 g/day of a mixture of essential amino acids (lysine, threonine, tryprophan, histidine, and tyrosine) and keto analogues of isoleucine, leucine, phenylalanine, valine, and methionine. A control group of 11 patients received no supplementation. All patients were on a liberal food intake amounting to 1 g of protein per kilogram of body weight and 31 kcal/kg of body weight daily. Before and 3 months after the beginning of the supplementation, the following parameters were measured: amino acids, albumin, transferrin, urea and creatinine concentrations in plasma, hemoglobin, and hematocrit in blood. None of these parameters was altered by either treatment. It is concluded that supplementation with essential amino acids or their keto analogues is ineffective in well-nourished dialysis patients.

Influence of essential amino acids and keto acids on protein metabolism and the anaemia of patients on chronic intermittent haemodialysis.

Ten patients were treated with 10 g essential amino acids per day orally; 9 patients received 9.5 g of a mixture of essential amino acids (Lys, Thr, Try, His, Tyr) and ketoanalogues of Ile, Leu, Phe, Val, Met per day and a control group of 11 patients received no supplementation. All patients were on a liberal food intake amounting to 1g protein/kg body weight and 31 kcal/kg body weight daily. Before and three months after the beginning of supplementation the following parameters were measured: serum concentrations of albumin, transferrin, urea, creatinine, blood haemoglobin content and haematocrit, activities of the enzymes delta-aminolevulinic acid dehydrase and porpho-bilinogen desaminase, and globin synthesis in peripheral red blood cells. After treatment with either essential amino acids or keto acids a significant stimulation of globin synthesis occurred. None of the other parameters was altered. It is concluded that in well-nourished patients supplements of essential amino acids or keto acids are ineffective.