Inflation-deflation method for endoscopic evacuation of intracerebral haematoma.

BACKGROUND: Endoscopic evacuation of intracerebral haematoma (ICH) has the advantage of being less invasive than craniotomy, but limited visualisation and difficulties in haemostasis are still a concern. The collapse of the haematoma cavity limits the visualisation of the surgical field. Inflation of the haematoma cavity with saline irrigation improves visualisation and facilitates accurate intra-operative orientation. METHOD: A unique technique, the cavity inflation-deflation method can help in exploring the residual haematoma and accessing the bleeding points. We also developed a combined irrigation-coagulation suction tube that concentrates the capabilities of suction, irrigation and monopolar coagulation. FINDINGS: The use of this multifunctional dedicated instrument and its application in the cavity inflation-deflation method allows for easy identification of residual haematoma and bleeding vessels. Secure haemostasis can also be accomplished under clear visualisation. No surgical complications and rebleeding occurred in any patient following the procedure. Our results show that the median haematoma evacuation rate was 99% and the surgical outcome was satisfactory. CONCLUSIONS: The inflation-deflation method using a combined irrigation-coagulation suction tube can facilitate optimal evacuation of ICH with secure haemostasis. Although further accumulation of patients and careful analyses are needed to be known whether this procedure improves the clinical outcomes in the patients, the preliminary results of its application have been promising.

Effects of phosphodiesterase inhibitors on spontaneous electrical activity (slow waves) in the guinea-pig gastric muscle.

1. The effects of the phosphodiesterase inhibitors caffeine, theophylline, isobutylmethylxanthine (IBMX) and rolipram on spontaneous electrical activity (slow waves) were studied in the circular muscle of the guinea-pig gastric antrum. 2. All the inhibitors reduced slow wave frequency without changing the membrane potential and the slow wave configuration, but at higher concentrations they blocked the slow waves and caused membrane hyperpolarization. In the presence of the inhibitors a low level of irregular electrical activity could be observed in many preparations. 3. Isoprenaline, forskolin, dibutyryl cAMP and 8-bromo-cAMP all produced effects essentially similar to those of phosphodiesterase inhibitors. K+ (12 mM) and removal of K+ both depolarized the membrane and these were not affected by IBMX (1-3 microM). A decrease in frequency caused by IBMX was also not significantly affected by 12 mM K+ or K+ removal and only partially antagonized by TEA or 4-aminopyridine. 4. These results suggest that an increase in intracellular cAMP inhibits pacemaker activity of slow waves. An increase in K+ conductance does not seem to be a major factor in this inhibition. Slow waves appear to be a compound electrical activity in a group of muscle cells and are likely to be disintegrated by xanthine derivatives.

Sustained contraction produced by caffeine after ryanodine treatment in the circular muscle of the guinea-pig gastric antrum and rabbit portal vein.

1. Caffeine inhibited spontaneous mechanical activity at 0.3-1 mM, but produced a tonic contraction at concentrations higher than 3 mM in the circular muscle of the guinea-pig gastric antrum. In the circular muscle of the rabbit portal vein, caffeine at concentrations higher than 1 mM produced an early phasic contraction followed by a small tonic component. The caffeine-induced contraction was abolished by removal of the external Ca2+ more rapidly in the gastric antrum than the portal vein. 2. When the preparations were pretreated with ryanodine (1 microM) a sustained contraction developed on wash-out of caffeine (10 mM) both in the gastric antrum and portal vein. This contraction was not affected by nicardipine (3 microM) or verapamil (3 microM), but was readily abolished by removal of the external Ca2+ or by addition of cobalt (1 mM). Spontaneous electrical activity, the slow wave, in gastric muscles was blocked in the presence of 10 mM caffeine, but reappeared during the sustained contraction. 3. Both the contractions induced directly by caffeine and those produced following caffeine wash-out after ryanodine treatment were accompanied by a maintained increase in intracellular Ca2+ concentration measured with fura-2. 4. The presence or absence of Ca2+ during the application of ryanodine did not affect the ability of caffeine to initiate sustained contractions, provided Ca2+ was present during the exposure to caffeine. 5. It is concluded that caffeine can induce a sustained contraction after ryanodine treatment both in the guinea-pig gastric antrum and rabbit portal vein, by activating a Ca2+ influx pathway insensitive to organic Ca2+ channel blockers. No clear evidence was obtained for involvement of the Ca2+ influx pathway activated through depletion of intracellular Ca2+ stores. A hypothesis is proposed that the plasma membrane of these preparations is similar to the sarcoplasmic reticulum membrane in that Ca2+permeability can be increased almost irreversibly by a combination of caffeine and ryanodine in the presence of the external Ca2+.