Otosclerosis involving the vestibular aqueduct and Menière's disease

The coexistence of otosclerosis and endolymphatic hydrops in the temporal bone have been described; however, the mechanism for the development of endolymphatic hydrops in otosclerosis remains unknown. Among 128 temporal bones with otosclerosis, involvement of the vestibular aqueduct by otosclerosis was observed in four temporal bones from two patients. In all four, the vestibular aqueduct was filled with active otosclerotic foci; the lumen of the endolymphatic duct and sac was narrowed as a result of fibrosis, and endolymphatic hydrops, more severe in the pars inferior than the pars superior, was observed. Collapse of the ductus reuniens and dilated saccule was seen in three temporal bones. Our study indicates that otosclerotic obstruction of the vestibular aqueduct may create a disturbance of the outflow and/or absorption of endolymph, leading to the development of endolymphatic hydrops and Meniere's disease, thus supporting the theory of longitudinal flow of endolymph.     

Cholesterol granuloma of the peritoneum

Cholesterol granulomas are common in the mastoid region but have rarely been reported in other areas. The authors report the case of a 40-year-old man who had a cholesterol granuloma of the peritoneum. They discuss the morphology of the condition and the difficulties of diagnosis. It is likely that chronic or recurrent inflammation plays a major role in the pathogenesis and that, when dealing with such lesions preoperatively or intraoperatively, a radical approach may not be necessary.     

Cavernous sinus involvement in recurrent Nelson's syndrome

Summary Two cases of meningiomas, which are considered to have been caused by the preceding irradiation, are reported. In both cases, the cytokinetic study of the tumour using bromodeoxyuridine (BrdU) was performed. The percent of the tumour cells in the S phase of the cell cycle was less than 1% in both cases. The low labelling indices might suggest a relatively slow growing potential of these tumours, though the radiation-induced meningiomas were reported as being rapidly growing and malignant.     

Intrathecal injection of a specific enzyme in rats as a model for chemically induced spinal cord injury

A spinal cord injury model is described using chymopapain as a neurotoxic agent in rats. The trauma was evaluated by neurophysiological and morphological methods. Electrically evoked compound action potentials were used to quantify the neurophysiological effects caused by the injection of chymopapain into the lumbar dural theca in rats. A branch of the sciatic nerve was stimulated with voltage impulses of constant amplitude (40 V) and duration (0.1 ms) at the right external malleolus. The responses were recorded at the dorsal root entry zone L1. We used different doses of the enzyme (1000 i.u./ml; 2500 i.u./ml; 5000 i.u./ml). A total amount of 0.1 ml was injected into the rats' lumbar spinal canal intrathecally (n = 18). The control rate (n = 8) were subjected to exactly the same stimulus and recording procedures but the test solution was a corresponding volume of isotonic saline. Two hours after injection the animals were examined clinically and then sacrificed for histology. The prolongation of the latency of the electrically evoked potentials caused by the enzyme was very clear at the doses of 2500 i.u. and 5000 i.u. being about 10-15% relative to the mean latency before administration of the drug. The histological evaluation showed hemorrhage, vascular damage and indirect signs of myelin edema of the lumbar nerve tissue. Our study indicates that chymopapain injections into the lumbar spinal canal can be used as a reproducible model for spinal cord injury research.     

The influence of central haemodynamics on transcutaneous oxygen (TcpO2) measurements

Transcutaneous oxygen measurements (TcpO2) have been shown to be an index of tissue perfusion and it has been suggested that the main haemodynamic variable influencing tissue perfusion is cardiac output, assuming that inspired oxygen remains constant. To investigate this hypothesis we studied 23 consecutive patients in order to identify if changes in cardiac output correlated with similar changes in TcpO2 measurements. No correlation was found to suggest that cardiac output was the main haemodynamic determinant of TcpO2 measurements.     

Renal and hemodynamic effects of dopamine in infants following cardiac surgery

The renal and hemodynamic effects of dopamine were measured during the immediate postoperative period in six infants following repair of congenital cardiac defects. Dopamine was infused at rates of 5, 10, and 15 micrograms/kg/min. Cardiac index (CI) increased significantly at a dopamine infusion rate of 15 micrograms/kg/min. The glomerular filtration rate (GFR) and urine output increased at dopamine infusion rates of 5 and 10 micrograms/kg/min and returned to baseline at 15 micrograms/kg/min. No significant changes occurred in right atrial pressure (RAP), left atrial pressure (LAP), systemic artery pressure, systemic vascular resistance (SVR), or pulmonary vascular resistance (PVR). Heart rate (HR) increased slightly at a dopamine infusion rate of 15 micrograms/kg/min. Pulmonary artery pressure (PAP) increased significantly in only one patient. These data demonstrate that infants require high doses of dopamine to produce the hemodynamic effects seen in adults and that these higher doses may be used without adverse renal effects.     

Re-orchiopexy: advantages and disadvantages

Re-orchiopexy was performed in 33 boys (42 testes) in order to place an undescended testis in the scrotum after failure of the initial operation. Success was achieved in 80.9%. Seven of the 10 testes, reported to have short spermatic vessels at the first surgery, had no elongation of the vessels and only 1 of these resulted in a high scrotal location of the testis. It appears that most orchiopexy failures are the result of technical failures of the initial procedure. Standard orchiopexy with extensive mobilization of the spermatic vessels and testis can successfully correct most of the undescended testes. However, the preferred management for the intra-abdominal testis with short vessels may be transection of the spermatic vessels rather than a planned two-stage technique.     

End-to-end anastomosis by enclosure between a prosthesis and a vessel with a significant difference in diameter

A technique is described that allows an end-to-end anastomosis between a vascular prosthesis and a vessel that is much smaller in diameter. This procedure involves enclosing the prosthesis and the vessel while keeping the vascular axis straight without any kinking. In addition, this technique makes little demand on the extensibility of the natural tissue in order to adapt to the prosthesis, which is inextensible.     

The saphenous flap called the Acland's flap. Report of 2 cases]

The authors present two cases of Acland's flap. This flap described and published in 1981, is a very good flap, but the myocutaneous flaps have limited its use. However, the authors believe that there are indications for this saphenous flap. The vascular supply for this flap is a saphenous artery, the last branch of the femoral artery, before it becomes the popliteal artery. The authors report two cases: one neurovascular island flap for the posterior side of the knee, and the other case is a free flap for forearm. This flap is part of a particularly rich arterial network on the medial side of the thigh and of the knee. Masquelet, in 1986, showed that it is possible to raise a periosteal flap or a vascularized tendon flap.