In a controlled study, the cardiac involvement and arrhythmia profile of 32 patients with acromegaly were correlated with endocrine parameters (somatomedine C, growth hormone), clinical score and duration of the disease. Data were compared with those of 50 controls free of cardiac disease. Stress ECG, 24 h Holter monitoring and echocardiography were performed. Supraventricular premature complexes occurred no more often in acromegalics than in controls. Both prevalence and severity of ventricular arrhythmia, however, were significantly higher in patients compared to controls (P less than 0.01). 15/32 (48%) acromegalic patients had complex ventricular arrhythmias (Lown III-IV) as compared with 6/50 (12%) normal subjects (P less than 0.01). Repetitive ventricular arrhythmias (Lown IV a/b) occurred in 10/32 (31%) patients, but only in 4/50 (8%) controls (P less than 0.01). Furthermore, the frequency of ventricular premature complexes increased with duration of acromegaly (P less than 0.01). No correlation was found between the severity of ventricular arrhythmia and hormone levels. Left ventricular muscle mass was significantly increased (285 +/- 139 g, P less than 0.02) due to concentric hypertrophy. Severity of ventricular arrhythmias correlated with left ventricular mass and with clinical activity score (P less than 0.01). Thus, compared to controls, acromegalic patients show more frequent and complex ventricular arrhythmias and left ventricular hypertrophy. Duration of the disease rather than hormone levels seems to be relevant for these pathological changes.

ObjectiveRecent studies have investigated the role of spinal image guidance for pedicle screw placement. Many authors have observed an elevated placement accuracy and overall improvement of outcome measures. This study assessed a bi-institutional experience following introduction of the Renaissance miniature robot for spinal image guidance in Europe.MethodsThe medical records and radiographs of all patients who underwent robot-guided implantation of spinal instrumentation using the novel system (between October 2011 and March 2015 in Mainz and February 2014 and February 2016 in Regensburg) were reviewed to determine the efficacy and safety of the newly introduced robotic system. Screw position accuracy, complications, exposure durations to intraoperative radiation, and reoperation rate were assessed.ResultsOf the 413 surgeries that used robotic guidance, 406 were via a minimally invasive approach. In 7 cases the surgeon switched to conventional screw placement, using a midline approach, due to referencing problems. A total of 2067 screws were implanted using robotic guidance, and 1857 screws were evaluated by postoperative CT. Of the 1857 screws, 1799 (96.9%) were classified as having an acceptable or good position, whereas 38 screws (2%) showed deviations of 3–6 mm and 20 screws (1.1%) had deviations > 6 mm. Nine misplaced screws, implanted in 7 patients, required revision surgery, yielding a screw revision rate of 0.48% of the screws and 7 of 406 (1.7%) of the patients. The mean ± SD per-patient intraoperative fluoroscopy exposure was 114.4 (± 72.5) seconds for 5.1 screws on average and any further procedure required. Perioperative and direct postoperative complications included hemorrhage (2 patients, 0.49%) and wound infections necessitating surgical revision (20 patients, 4.9%).ConclusionsThe hexapod miniature robotic device proved to be a safe and robust instrument in all situations, including those in which patients were treated on an emergency basis. Placement accuracy was high; peri- and early postoperative complication rates were found to be lower than rates published in other series of percutaneous screw placement techniques. Intraoperative radiation exposure was found to be comparable to published values for other minimally invasive and conventional approaches.

The authors found the preoperative 3D model to be in high concordance with intraoperative conditions; the resulting intraoperative "déjà-vu" feeling enhanced surgical confidence. In all procedures planned with the Dextroscope, the chosen surgical strategy proved to be the correct choice. Three-dimensional virtual reality models of a patient allow quick and easy understanding of complex intracranial lesions.

Purpose: To determine if the diffusion tensor imaging (DTI) parameters fractional anisotropy (FA) and mean diffusivity (MD) can differentiate between accompanying edema and tumor cell infiltration of white matter (WM) beyond the tumor edge as defined from conventional MRI in low-and high-grade gliomas. Materials and Methods:We examined 12 patients with high-grade gliomas/glioblastomas and eight patients with low-grade gliomas and compared them to 10 patients with meningiomas, in which no tumor infiltration is expected. The tumor was defined as the enhancing area in glioblastomas and meningiomas and as the area of increased T2-signal in low-grade gliomas. FA and MD were measured in the center of the tumor and in the adjacent WM. The contralateral WM and internal capsule were used as an internal standard. Results:Comparing the WM areas of increased T2-signal adjacent to meningiomas and glioblastomas, we saw a trend (without significance) towards a reduction of FA, but not of MD, in glioblastomas. We found no changes of FA and MD in the WM adjacent to low-grade gliomas (without T2-signal increase) compared to the WM of the contralateral hemisphere. In meningiomas and high-grade gliomas/ glioblastomas, a narrow rim of significantly (P Ͻ 0.01) increased FA and decreased MD values around the enhancing tumor area was seen, whereas in low-grade gliomas, such a rim could not be defined. There was no contribution of FA or MD to grading of gliomas. Conclusion:In glioblastomas, a reduction of FA in the edematous area surrounding the tumor may indicate tumor cell infiltration, but a reliable differentiation between infiltration and vasogenic edema is not yet possible on the basis of DTI. The additional finding of a narrow rim of increased FA and decreased MD at the edge of glioblastomas (as well as in meningiomas) may be caused by compressed WM fibers and/or increased vascularity, but does not contribute to exclude peripheral cellular infiltration.

In this study, the technical aids yielded discordant results in 14% of cases, necessitating interpretation by an expert examiner. The perfusion tests, in particular, can give false-positive results in patients with large cranial defects, skull fractures, or cerebrospinal fluid drainage. In such cases, electrophysiologic tests or a repeated clinical examination should be performed instead. CTA is a promising, highly reliable new method for demonstrating absent intracranial blood flow. In our view, it should be incorporated into the German guidelines for the diagnosis of brain death.