Juergen Honegger

Contemporary microsurgical concept for the treatment of Cushing's disease: endocrine outcome in 83 consecutive patients.

Background  Evidence suggests that occult adenoma remnants are responsible for persistent Cushing’s disease (CD) following transsphenoidal surgery (TSS). To optimize the outcome, we have adapted our microsurgical concept. The influence of our surgical strategy on remission rate and pituitary function is presented.

Growth modelling of non-functioning pituitary adenomas in patients referred for surgery

OBJECTIVE Recent observational studies have established progression and recurrence rates of pituitary adenomas. However, it is still unknown how individual pituitary adenomas grow over years and whether growth kinetics follow a distinct growth model. The objective of this study was to define a growth model for non-functioning pituitary adenomas. METHODS Fifteen patients who had five or more serial high-quality examinations with magnetic resonance images or computerized tomography scans were identified among 216 patients with non-functioning pituitary adenomas. Tumour volumes were assessed using a stereological method based on the Cavalieri principle. Tumour growth during the observation period was analysed and different growth models were fitted to the data. RESULTS Fifteen pituitary adenomas (12 recurrent tumours and 3 newly diagnosed tumours) were longitudinally observed during a median observation period of 7.4 years (range: 2.3-11.9 years). Growth kinetics could be described either by an exponential growth model (nine patients) or by a logistic model (five patients) with initial exponential growth followed by deceleration of growth. One tumour remained unchanged in size during the observation period. None of the adenomas showed accelerated growth during the observation period. Overall, the linear growth model was not suitable to describe the growth kinetics of non-functioning pituitary adenomas. CONCLUSIONS Our study shows that growth of pituitary adenomas can be described by distinct growth models. Knowledge of growth dynamics has implications for clinical practice and helps to adjust scanning protocols for follow-up investigations.

The development of the Tuebingen Cushing’s disease quality of life inventory (Tuebingen CD-25). Part I: construction and psychometric properties

Objective  To develop a disease‐specific questionnaire for Cushing’s disease (CD), the Tuebingen Cushing’s disease quality of life inventory (Tuebingen CD‐25).

Reduced intercarotid artery distance in acromegaly: pathophysiologic considerations and implications for transsphenoidal surgery.

BACKGROUND The objective of this study is to evaluate the significance of reduced intercarotid artery distance in the C5 segment in acromegalic patients and the implications for transsphenoidal surgery. METHODS The skull base with the carotid canal was examined with a helical CT scan in 45 patients with acromegaly and 45 age group-matched controls. The distances between the inner walls (IWs) of the carotid sulcus (CS), the outer walls (OWs) of the CS, and the diameter of the ICA at the C5 segment were assessed. Preoperative IGF-1 and growth hormone levels and concomitant diseases were evaluated and correlated with the biometric findings. Statistical analysis was performed with JMP (JMP version 7.0.2, SAS, Cary, USA). RESULTS The mean distance between the IW was 1.64 +/- 0.40 cm in the acromegalic patients and 1.90 +/- 0.26 cm in the control group (P = .0005). The distance between the OW measured 3.01 +/- 0.39 and 2.97 +/- 0.33 cm in the acromegalics and in the control group, respectively (P = .6230). The difference in the diameter of the ICA was statistically significant (P < .0001) between patients and control group. Within the patient group, the distance between the IW of both ICA was significantly smaller in the subgroup with arterial hypertension (P = .0256). CONCLUSION Narrowing of the inner borders of the CS between the right and left side is a statistically significant parameter in acromegaly. Attention should be given to an altered vascular course of the ICAs when planning and performing transsphenoidal microsurgery in acromegalic patients. A preoperative skull base CT may furnish important anatomical information and further reduce the risk of vascular injury.

The development of the Tuebingen Cushing's disease quality of life inventory (Tuebingen CD-25). Part II: normative data from 1784 healthy people

Objective  In part I of the study, a health‐related quality of life (HRQoL) inventory for Cushing’s disease (CD), the Tuebingen Cushing‐25 quality of life inventory (Tuebingen CD‐25) was developed. In this second part, we aimed to assess normative data from healthy controls (HC) with which the individual patients’ scores can be compared.

Primary intrasellar schwannoma: clinical, aetiopathological and surgical considerations.

Schwannomas originating within the sella turcica are extremely rare. We describe the clinical, radiological and intraoperative findings of a patient with an intrasellar and suprasellar schwannoma. Gross total tumour removal was performed by a trans-sphenoidal approach. Perivascular or ectopic Schwann cells, lateral nerve plexus within the cavernous sinus, as well as Schwann cells from small nerve twigs of the dura are some of the current histopathological hypotheses for the origin of these lesions.

Craniometric changes in patients with acromegaly from a surgical perspective

OBJECT The objective of this study was to evaluate and analyze morphometric and volumetric changes of the skull due to acromegaly in areas relevant for neurosurgical practice, focusing on the surgical implications. METHODS On preoperatively acquired CT scans, cephalometric and volumetric measurements were performed on 45 patients with acromegaly (Group A) and 45 control patients (Group B). The authors determined thickness of the cranial vault, inner and outer diameters of the skull, and the diameter of sphenoidal and maxillary sinus, as well as frontal and maxillary sinus volumetry. The morphometric and volumetric CT data of the patients with acromegaly were compared with the data of a control group and correlated with clinical parameters. RESULTS Cranial vault thickness differed significantly (p < 0.0001) between the 2 groups. A correlation of the vault thickness with preoperative human growth hormone, insulin-like growth factor-I levels, and duration of clinical history in acromegaly could not be established. The outer anterior-posterior skull diameter of Group A (18.47 ± 0.94 cm) differed significantly (p = 0.0146) from Group B (17.98 ± 0.93 cm) and correlated significantly with preoperative human growth hormone (r = 0.3277; p = 0.0299) and insulin-like growth factor-–I serum levels (r = 0.3756; p = 0.0120). Measurements of the anterior-posterior diameter of the sphenoidal sinus differed significantly (p = 0.0074) between patients with acromegaly and controls. Volumetric analysis of the frontal sinus resulted in a statistically significant difference (p = 0.0382) between patients with acromegaly (14.89 ± 10.85 cm3) and controls (10.06 ± 6.93 cm3). CONCLUSIONS Significant craniometric changes and volumetric remodelling of the paranasal sinus occur in acromegaly. The bone alterations are of surgical importance for using the transsphenoidal approach. Detailed preoperative diagnostic examination and planning as well as selection of appropriate instruments are mandatory for safe and successful pituitary adenoma removal in patients with acromegaly.

Tuebingen CD-25 Is a Sensitive Tool to Investigate Health-Related Quality of Life in Cushing's Disease Patients in the Course of the Disease

Background: The primary object was to investigate whether the Tuebingen CD-25 captures changes in health-related quality of life (HRQoL) sensitively in Cushings disease (CD) and to identify factors that favour postoperative HRQoL. Methods: 17 CD patients were scheduled for transsphenoidal tumour removal and filled out the inventory before and after surgery. The mean time elapsed after surgery was 14.4 ± 11.3 months. All patients were in remission at the second timepoint of investigation. Results: HRQoL as assessed with the Tuebingen CD-25 improved significantly after successful surgical tumour removal. A large effect size (Cohens d = 0.84) in the total score indicates good sensitivity to change. 13 patients (76.5%) showed impaired HRQoL preoperatively compared with a general population sample. Postoperatively, 35.3% of the patients still suffered from an impaired HRQoL. Stepwise linear regression analysis revealed that less comorbidities (≤2) and greater morning cortisol decrease were promotive factors for better postoperative HRQoL (p < 0.05). The postoperative improvement in HRQoL could be best predicted by the presence of preoperative HRQoL impairment and age of the patients, i.e. patients who were younger were more likely to improve. Moreover, patients without postoperative pituitary deficiencies improved significantly more in the cognition scale. A tendency towards more improvement in overall HRQoL was observed in non-hypocortisolaemic patients. Conclusions: The Tuebingen CD-25 has proved to be a capable and sensitive instrument to investigate HRQoL in the course of disease. The number of postoperative comorbidities had the greatest impact on postoperative well-being.

Predictors for visual dysfunction in nonfunctioning pituitary adenomas - implications for neurosurgical management.

Despite ample experience with surgical treatment of nonfunctioning pituitary adenomas, objective data defining the risk for visual compromise depending on the suprasellar extension in pituitary adenomas are sparse.

Developments in neuroendoscopy: trial of a miniature rigid endoscope with a multidirectional steerable tip camera in the anatomical lab

The aim of this study is to assess field of view, usability and applicability of a rigid, multidirectional steerable video endoscope (EndActive) in various intracranial regions relevant to neurosurgical practice. In four cadaveric specimens, frontolateral, pterional, transnasal (to sella and clivus), interhemispheric (transcallosal and retrocallosal) and retrosigmoid approaches as well as precoronal burr holes for ventriculoscopy were performed. Anatomical target structures were defined in each region. We assessed field of view as well as optical and ergonomic features of the prototype. The EndActive is a 4-mm-diameter rigid video (endo)scope with an integral image sensor comprising an embedded light source. The viewing direction in a range of 160° can either be controlled by the computer keyboard or a four-way joystick mounted to the handle section of the endoscope. The endoscopic imaging system allows the operator to simultaneously see both a 160° wide-angle view of the site and an inset of a specific region of interest. The surgeon can hold the device like a microsurgical instrument in one hand and control movements precisely due to its reduced weight and ergonomic shape. The multiplanar variable-view rigid endoscope proved to be useful for following anatomical structures (cranial nerves I–XII). The device is effective in narrow working spaces where movements jeopardize the delicate surrounding structures. The multiplanar variable viewing mechanism in a compact device offers advantages in terms of safety and ergonomics. Improving the usability will probably optimize the applicability of endoscopic techniques in neurosurgery.