David Netuka

One Year Experience with 3.0 T Intraoperative MRI in Pituitary Surgery

A multifunctional surgical suite with intraoperative 3.0 T MRI (ioMRI) has been operating at the Central Military Hospital, Prague since April 2008. Our experiences over the past year and the effect of ioMRI on the extent of pituitary adenoma resection are evaluated. Eighty-six pituitary adenoma resections were performed in 85 patients with ioMRI in the first year of the ioMRI service. Pituitary adenoma suprasellar extension was present in 60 cases, invasion into cavernous sinus in 49 cases, and retrosellar growth in one case. The surgical goal was set before surgery: either a radical resection (49 cases) or a partial resection (37 cases). In the group of patients where a decision for a radical resection was taken the results are as follows: ioMRI confirmed radical resection in 69.4% of the cases; ioMRI disclosed unexpected adenoma residuum and further resection led to radical resection in 22.4%. In the group of patients where a decision for a partial resection was taken, the results are as follows: no further resection was perfomed after ioMRI in 51.3% of the cases and further resection was performed after ioMRI in 48.7% of the cases. ioMRI seems to be a valuable tool to increase the extent of pituitary adenoma resection.

Comparison between degree of carotid stenosis observed at angiography and in histological examination

SummaryBackground. The generally accepted indications for carotid endarterectomy are the clinical picture and degree of per cent stenosis of the carotid artery. Despite the fact that stenosis measurement is defined, the methods vary considerably. The correlation of particular methods, especially angiography and duplex sonography, has been repeatedly demonstrated. However, the correlation between any technique and true anatomical stenosis, as evaluated on the surgical specimen, has been only anecdotally reported. Method. During carotid endarterectomy, the atherosclerotic plaque was removed in one piece and subsequently stored and histologically processed. The histological slides were evaluated under an optical microscope, scanned and the slide with maximum stenosis was determined using a planimetric program. Both the minimal lumen area and the area of the whole plaque were measured. The stenosis was calculated using the planimetric method. On the maximum stenosis slice, the minimal diameter and the diameter of the whole plaque were also measured. Angiographic images were scanned and the per cent stenoses were remeasured, according to the NASCET and ECST criteria. In total, of 147 cases, all above-mentioned parameters were obtained. Student’s t tests for paired samples were used to evaluate the results. Findings. The t-tests indicated significant differences between the per cent stenosis as measured on the anatomical specimen and on the angiogram (p<0.05). The results indicate that the angiographic measurement underestimates the degree of in-situ anatomical stenosis. The underestimation was more marked the less the degree of stenosis. Conclusions. Our study finds that per cent stenosis measurement obtained by angiography with NASCET or ECST methods does not reliably reflect the anatomical degree of per cent stenosis, which makes questionable the rigorous following of percentage stenosis using angiography as the sole indicator for carotid endarterectomy in all cases.

Dopamine 2 receptor expression in various pathological types of clinically non-functioning pituitary adenomas

Clinically non-functioning pituitary adenomas account for about one-third of pituitary tumors. The majority of them are pathologically classified as gonadotropinomas or null-cell adenomas without hormonal expression. The rest represent silent corticotroph adenomas and plurihormonal tumors. Conservative therapy with dopamine agonists is effective in some cases only depending on the expression of dopamine 2 receptors (D2R). The aim of this study was to quantitatively estimate D2R expression in clinically non-functioning pituitary adenomas and correlate the results with adenoma type according to pathological classification. Out of the 87 adenomas investigated, 63 expressed gonadotropins, 7 were silent corticotroph adenomas, 7 were plurihormonal tumors, and only 6 did not express any pituitary hormone on immunohistochemical investigation. With the use of the reverse transcriptase PCR technique, D2R mRNA was expressed in all adenomas with very heterogeneous quantity. The expression was very low in corticotroph adenomas (relative median quantity after normalization to housekeeping gene 0.01) and lower in plurihormonal tumors (median 0.4) than in gonadotroph (median 1.3) and null-cell adenomas (median 1.9). The difference between corticotroph adenomas and plurihormonal tumors in comparison with other pathological types was statistically significant. The expression of D2R did not depend on the presence or absence of gonadotropins. We conclude that D2R expression is very low in corticotroph adenomas and significantly lower in plurihormonal tumors. The positivity of gonadotropins does not predict the D2R quantity.

Accuracy of angiography and Doppler ultrasonography in the detection of carotid stenosis: a histopathological study of 123 cases

SummaryBackground. A prospective study was performed comparing the accuracy of digital subtraction angiography (DSA) and Doppler ultrasonography (DUS) stenosis findings with measurements on histological specimens.Method. DSA and DUS were used to evaluate carotid stenosis and were compared with measurements on histological specimens. Intact carotid plaques from 123 cases were removed in one piece during surgery. The specimens were histologically processed and examined in transverse sections. The smallest inner and correlating outer diameters were measured and the extent of stenosis was calculated. Carotid artery stenoses were compared and statistics done. Specimens in symptomatic cases were divided into 3 groups: stenosis 30–49% (Group 1), stenosis 50–69% (Group 2) and stenosis 70–99% (Group 3). Specimens in asymptomatic cases were divided into two groups: stenosis ≤59% (Group A) and stenosis ≥60% (Group B).Findings. Wilcoxon paired tests revealed significant differences between DSA, DUS and measurements on histological specimens. In severe stenoses only, no significant difference was observed between stenosis measurement according to the European Carotid Surgery Trial (ECST) angiography methodology and measurements on histological specimens. The most pronounced differences were found between angiography methodology of the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and measurements on histological specimens. When investigating how often preoperative measurement classified stenosis into the same Group of stenoses as postoperative measurement, DUS was the most accurate diagnostic tool.Conclusions. This study confirmed our previous results, i.e., angiography underestimates the degree of carotid artery stenosis. DUS seems to be more accurate in classifying stenoses into different groups to the extent of narrowing of the carotid arteries. These results make the position of angiography in diagnostic algorithm of carotid stenoses investigations even more questionable.

Cognitive functions before and 1 year after surgical and endovascular treatment in patients with unruptured intracranial aneurysms

Background and purpose. This prospective study investigated whether surgery or endovascular treatment for unruptured intracranial aneurysms (UIAs) affects cognitive functions. Methods. Four neuropsychological variables from an Auditory Verbal Learning Test (overall capacity of verbal memory and delayed recall) and a Trail Making Test (psychomotor speed and cognitive flexibility) were investigated before and 1 year after treatment for UIAs in 65 patients < 61 years of age. This cohort consists of 15 men and 50 women aged 15–60 (mean age 44.9) years. Results. Group-rate analysis showed a non-significant increase in post-treatment scores in the four neuropsychological variables. In addition, no significant differences were found between the surgical clipping (SC) and endovascular coiling (EC) group. Event-rate analysis demonstrated that two patients from the EC and one from the SC group developed cognitive impairment after treatment. Conclusions. Surgical and endovascular repair for UIAs do not impair cognition in patients without postoperative restrictions in lifestyle.

Quality of life 1 year after aneurysmal subarachnoid hemorrhage in good outcome patients treated by clipping or coiling.

BACKGROUND AND PURPOSE A study was conducted to compare the quality of life (QOL) of surgically versus endovascularly treated patients with ruptured cerebral aneurysms. METHODS We treated 45 patients surgically (surgical clipping [SC] group) and 44 by endovascular therapy (coil embolization [CE] group). A standardized test of QOL and a structured interview were employed to assess changes 1 year after subarachnoid hemorrhage (SAH). One neurosurgical team using the same treatment protocols treated all patients. The SC and CE groups did not differ significantly in age, sex, education, aneurysm size, Hunt and Hess grade, Glasgow outcome scale (GOS) score, and intelligence quotient (IQ). RESULTS Generally, the patients reported psychological changes (impairment in memory, 47%; concentration, 20%; and ability to learn new things, 12%), which they subjectively related to SAH. On the one hand, 31% of the patients believed that close relatives noticed changes in their psychological condition as a result of the intervention. On the other hand, 61% reported an unaltered economic situation, 51% were well adjusted in work, and 70% claimed their family relationships remained unchanged. In comparison with the controls, patients claimed to have lower QOL in the areas of sexuality, love, psychic well-being, physical autonomy, and health. No differences in QOL were found between the SE and CE groups. CONCLUSIONS The differences in QOL in the patients treated by either coiling or clipping were small and nonsignificant. Participants in both groups mentioned lower QOL in the areas of intimate relationships and health.

Clinical impact of a high-frequency seizure onset zone in a case of bitemporal epilepsy

High-frequency activity has been described as having a role in the initiation of epileptic seizures. The case of a patient with refractory bitemporal epilepsy is presented. Extraoperative monitoring with depth and subdural electrodes revealed an ictal pattern with a build-up of high-frequency (> 80 Hz) activity originating in the cortex, with spread to both hippocampi. This observation was only revealed with the use of high-pass filtering, and represented crucial information that significantly influenced the decision about the side, localization and extent of resection. Removal of the cortex generating high-frequency activity, led to cessation of seizures in this patient. Current knowledge about the role of high-frequency activity and the case presented here support the importance of recording with equipment capable of detecting fast activity during the presurgical invasive monitoring. An active search for a high-frequency seizure onset zone in patients with structurally-unaffected hippocampi may improve the outcome beyond that possible with conventional bandwidth, invasive EEG recordings.

Intraoperative Magnetic Resonance Imaging During Endoscopic Transsphenoidal Surgery of Growth Hormone-Secreting Pituitary Adenomas

BACKGROUND The effect of intraoperative magnetic resonance imaging (iMRI) on the extent of sellar region tumors treated endonasally has been described in previous research. However, the effects of iMRI on endocrinologic outcome of growth hormone-secreting adenomas have been studied in only a few small cohort studies. METHODS Inclusion criteria were primary transsphenoidal surgery for growth hormone-secreting adenoma from January 2009 to December 2014, a minimum follow-up of 1 year, complete endocrinologic data, at least 1 iMRI, and at least 2 postoperative magnetic resonance images. The cohort consisted of 105 patients (54 females, 51 males) with a mean age of 48.3 years (range, 7-77 years). There were 16 microadenomas and 89 macroadenomas. RESULTS Endocrinologic remission in the whole cohort was achieved in 64 of the patients (60.9%). Resection after iMRI was attempted in 22 of the cases (20.9%). Resection after iMRI led to hormonal remission in 9 cases (8.6%). Endocrinologic postoperative deficit was observed in 10 cases (12.5%). Postoperative cerebrospinal fluid leakage indicated the necessity to reoperate in 3 cases (3.8%). No neurologic deterioration was observed. CONCLUSIONS iMRI influences not only the morphologic extent of pituitary adenomas resection but also the endocrinologic results. We encourage the routine application of iMRI in pituitary adenoma surgery, including hormone-secreting pituitary tumors.

Melatonin and cortisol secretion profile in patients with pineal cyst before and after pineal cyst resection

A pineal cyst is a benign affection of the human pineal gland on the borderline between pathology and normality. Only a small percentage of patients present with symptoms and a surgical treatment is indicated in highly selected cases. A melatonin secretion in patients with a pineal cyst before and after a pineal cyst resection has not been studied yet and the effect of surgery on human metabolism is unknown. The present study examined melatonin, cortisol and blood glucose secretion profiles perioperatively in a surgical group of 4 patients. The control group was represented by 3 asymptomatic patients with a pineal cyst. For each patient, 24-h circadian secretion curves of melatonin, cortisol and glycemia were acquired. An analysis of melatonin profiles showed an expected diurnal pattern with the night peak in patients before the surgery and in the control group. In contrast, melatonin levels in patients after the surgery were at their minimum throughout the whole 24-h period. The cortisol secretion was substantially increased in patients after the surgery. Blood glucose sampling showed no statistically significant differences. Clinical results demonstrated statistically significant headache relief measured by Visual Analogue Scale in patients after the surgery. Despite the small number of examined patients, we can conclude that patients with a pineal cyst preserved the physiological secretion of the hormone melatonin while patients who underwent the pineal cyst resection experienced a loss of endogenous pineal melatonin production, which equated with pinealectomy. Surprisingly, cortisol secretion substantially increased in patients after the surgery.

Flexible endoscope-assisted evacuation of chronic subdural hematomas

BackgroundChronic subdural hematoma (CSDH) is a common neurosurgical condition with an increasing incidence. Standard treatment of CSDHs is surgical evacuation. The objective of this study is to present a modification of standard burr-hole hematoma evacuation using a flexible endoscope and to assess the advantages and risks.MethodsProspectively, 34 consecutive patients diagnosed with CSDH were included in the study. Epidemiological, clinical and radiographical data were collected and reviewed. All patients underwent a burr-hole evacuation of CSDH. A flexible endoscope was inserted and subdural space inspected during surgery. The surgeon was looking specifically for the presence of septations, draining catheter position and acute bleeding.ResultsThirty-four patients underwent 37 endoscope-assisted surgeries. Presenting symptoms were hemiparesis (79%), decreased level of consciousness (18%), gait disturbances (15%), headache (12%), aphasia (6%), cognitive disturbances (6%) and epileptic seizure (3%). Average operative time was 43 min, and the average increase in operative time due to the use of the endoscope was 6 min. Recurrence rate was 8.8%, and clinical outcome was favorable (defined as mRS ≤ 2) in 97% of the cases.ConclusionsTo our knowledge, the present cohort of 34 patients is the largest group of patients with CSDH treated using an endoscope. This technique allows decent visualization of the hematoma cavity while retaining the advantages of a minimally invasive approach under a local anesthesia. The main advantages are correct positioning of the catheter under visual control, identification of septations and early detection of cortex or vessel injury during surgery.