Surgical approach for tentorial meningiomas in cats: a review of six cases

The surgical technique for removal of tentorial meningiomas is described on six cats using a unilateral temporal supracerebellar transtentorial approach. Complete gross tumour resection was achieved in four of six cats. In one cat, only subtotal resection was achieved. One cat died shortly after surgery because of extensive cerebral haemorrhage. The surgical approach, combined with cisternal or ventricular cerebrospinal fluid puncture and an open-window technique (tumour fenestration and enucleation) provided sufficient visibility and tumour accessibility without excessive manipulation of the brain parenchyma. In all patients, a postoperative transient worsening of the clinical signs was observed. The neurological signs resolved with time with the exception of blindness in two cats. All five surviving cats were monitored for a mean follow-up time of 19 months (median 20 months; range 6-30 months). All patients died or were euthanased because of tumour regrowth within the follow-up period. Although challenging, surgical treatment is a useful therapeutic measure in the treatment of cats presenting with tentorial meningiomas.

Image-guided surgical microscope with mounted minitracker

A new image-guided microscope using augmented reality overlays has been developed. Unlike other systems, the novelty of our design consists in mounting a precise mini and low-cost tracker directly on the microscope to track the motion of the surgical tools and the patient. Correctly scaled cut-views of the pre-operative computed tomography (CT) stack can be displayed on the overlay, orthogonal to the optical view or even including the direction of a clinical tool. Moreover, the system can manage three-dimensional models for tumours or bone structures and allows interaction with them using virtual tools, showing trajectories and distances. The mean error of the overlay was 0.7 mm. Clinical accuracy has shown results of 1.1-1.8 mm.

The relationship between coagulation and the extend of surgery and postoperative infection in surgical infants below 6 months of age

AIM: First to assess coagulation changes after surgery in children below 6 months of age. Second to detect differences attributable to the extent of surgery and postoperative infection. MATERIALS AND METHODS: Blood counts, haemoglobin concentration (Hb), haematocrit (Ht), prothrombine time (PT), activated partial thromboplastine time (aPTT) and thrombelastography (TEG) were studied pre- and 2+/-1/2 d postoperatively. Patients were divided in 3 groups. I: minor surgery without access to the abdomen or thorax (n=51); II: abdominal or thoracic interventions (n=24); III: abdominal surgery with postoperative sepsis (n=11). RESULTS: Preoperative values of Hb, Ht and INR were related to the age of the infant. Postoperatively clot strength and formation rate increased in gr. I (p<0.05). In gr. II, clot formation was initiated earlier (p<0.05) even though PT decreased (p<0.05). In group III, patients postoperatively developed a tendency for hypocoagulability in all TEG-parameters, but not in plasmatic coagulation. Postoperative TEG measurements were significantly inferior in gr. III when compared to gr. I and II. CONCLUSION: Our findings suggest activation of whole blood coagulation in the uncomplicated postoperative period despite of a decrease in plasmatic coagulation. In sepsis, only thrombelastography, but not plasmatic coagulation was affected.