Amir R. Dehdashti

Pure endoscopic endonasal approach for pituitary adenomas: early surgical results in 200 patients and comparison with previous microsurgical series.

OBJECTIVEnThe aim of this study was to report the results of a consecutive series of patients undergoing pituitary surgery using a pure endoscopic endonasal approach and to evaluate the efficacy and safety of this procedure.nnnPATIENTS AND METHODSnWe reviewed 200 consecutive patients with pituitary adenoma who underwent purely endoscopic transsphenoidal resection of their lesions. The patients clinical outcomes, including remission rates, degrees of tumor removal, and complications, were evaluated and compared with a previous microscopic series.nnnRESULTSnThere were 111 nonfunctioning adenomas and 34 growth hormone-secreting, 27 adrenocorticotropin hormone-secreting, 25 prolactin-secreting, and 3 thyroid-stimulating hormone-secreting adenomas. The degree of gross total removal for tumors with suprasellar or parasellar extension and without cavernous sinus involvement was 96% and for intrasellar lesions was 98%. After a median follow-up period of 19 months, the remission results for patients with functioning adenomas were 71% for growth hormone-secreting, 81% for adrenocorticotropin hormone-secreting, and 88% for prolactin-secreting adenomas, with no recurrence at the time of the last follow-up. This compares with similar results reported from series using a standard microsurgical approach (growth hormone-secreting adenomas, 67%; adrenocorticotropin hormone-secreting adenomas, 78%; and prolactin-secreting adenomas, 62%). Endoscopic surgery for recurrent or residual nonfunctioning adenomas that had been previously treated using a microscopic approach revealed in the majority of cases a more limited exposure during the initial surgery, frequently with incomplete tumor removal. Complication rates have been low, and the average length of hospital stay was reduced.nnnCONCLUSIONnA purely endoscopic approach for pituitary adenoma treatment is a safe and effective alternative to the traditional microscopic procedure. Although our results reveal excellent tumor-removal rates, comparable remission rates in functioning tumors, and a very low rate of complications, additional studies with longer follow-up periods are required to confirm whether this approach should be considered the preferred procedure for pituitary surgery.

Expanded endoscopic endonasal approach for anterior cranial base and suprasellar lesions: indications and limitations.

OBJECTIVEThe traditional boundaries of the transsphenoidal approach can be expanded to include the region from the cribriform plate of the anterior cranial fossa to the foramen magnum in the anteroposterior plane. The introduction of endoscopy to transsphenoidal surgery, with its improved illumination and wider field of view, has added significant further potential for the resection of a variety of cranial base lesions. We review our experience with the expanded endoscopic endonasal approach in a series of 22 patients with anterior cranial base and supradiaphragmatic lesions. METHODSFrom June 2005 to June 2007, the expanded endoscopic endonasal approach was used in 22 patients with the following pathologies: 6 craniopharyngiomas; 4 esthesioneuroblastomas; 3 giant pituitary macroadenomas; 2 suprasellar Rathkes pouch cysts; 2 angiofibromas; and 1 each of suprasellar meningioma, germinoma, ethmoidal carcinoma, adenoid cystic carcinoma, and large suprasellar arachnoid cyst. This study specifically focused on the surgical indications and approaches to these lesions and the surgical results, complications, and limitations associated with this technique. RESULTSGross total tumor removal, as assessed by postoperative magnetic resonance imaging, was possible in the majority of patients (73%), with the exception of the craniopharyngioma group, in which only 1 lesion was completely removed. There were no permanent neurological complications except for increased visual disturbance in 1 patient. Other complications included cerebrospinal fluid fistulae in 4 patients (18%) and meningitis in 1 patient (5%). There was no operative mortality. Large lesions, significant lateral extension, encasement of neurovascular structures, and brain invasion in malignant lesions are considered some of the contraindications for this technique. CONCLUSIONThe expanded endoscopic endonasal approach is a promising minimally invasive alternative to open transcranial approaches for selective lesions of the midline anterior cranial base. The avoidance of craniotomy and brain retraction and reduced neurovascular manipulation with less morbidity are potential advantages. Major complications have been few, but there are also limitations with this technique. This approach should be included in the armamentarium of cranial base surgeons and considered as an option in the management of selected patients with these complex pathologies.

Expanded endoscopic endonasal approach for treatment of clival chordomas: early results in 12 patients.

OBJECTIVEWe report our recent experience with an expanded purely endoscopic endonasal approach for the treatment of clival chordomas. METHODSTwelve patients underwent an expanded endoscopic approach for excision of cranial base chordomas at Toronto Western Hospital. Two patients had undergone a previous craniotomy for excision of a significant lateral intracranial extension of the tumor. All other patients had mainly centrally located lesions. Three patients had recurrent tumors. This study focused on the surgical approach, results, and complications associated with this approach. RESULTSDiplopia caused by VIth nerve palsy was the most common presenting symptom and was observed in seven patients. Gross total resection of the tumor was achieved in seven patients (58%). Four patients had complete recovery of their preoperative diplopia. One patient (8%) presented with new hemiparesis postoperatively. Four patients (33%) had a cerebrospinal fluid leak postoperatively; two were treated by lumbar drainage, and two required a secondary surgical repair. All newly diagnosed patients underwent adjuvant radiotherapy. There was no mortality. The short-term outcome was excellent in all but one patient. No recurrence was observed at the median follow-up period of 16 months. CONCLUSIONThe expanded endoscopic endonasal approach is a valid minimally invasive alternative for the treatment of centrally located clival chordomas or as an adjunct for the central part of chordomas with lateral extension. The early results of this technique indicate at least equivalency to more extensive open approaches, and its versatility may widen the horizon of surgical management of these aggressive lesions. The challenge with the cerebrospinal fluid leakage is being addressed with novel local flap repair techniques. This approach should be in the armamentarium of cranial base surgeons as an option in the management of clival chordomas.

Fronto-basal interhemispheric approach for tuberculum sellae meningiomas; long-term visual outcome

We report our experience with the treatment of tuberculum sellae meningiomas using the fronto-basal interhemispheric approach. A retrospective analysis was performed on a series of 24 patients with tuberculum sellae meningiomas who were operated between March 2000 and January 2007. Patients presenting symptoms, radiological images, operative reports, and clinical follow-up data were reviewed with special consideration for visual outcome. Visual deterioration was the presenting symptom in all patients, followed by headache in 9 patients (37.5%). The average duration of visual symptoms was 17.6 months. The average tumor diameter was 2.63 cm; encasement of the carotid artery was identified in 7 patients (29%). Complete tumor removal was achieved in 21 patients (87.5%). Mean follow-up period was 52 months. Vision improved in 19 patients (79%), remained stable in 4 (17%) and deteriorated in 1 patient (4%). The degree of tumor removal or visual outcome were both unrelated to the tumor size (p = 0.2 and p = 0.6 respectively). While the degree of preoperative visual deficit did not affect the visual improvement rate in the whole group (p = 0.9), those patients with improvement to good functional vision (>20/40) after the surgery, had a less severe preoperative deficit (p < 0.001). The most common complication was anosmia (29.1%) and there was no mortality. The frontobasal interhemispheric approach is safe and provides a direct anatomical approach to tuberculum sellae meningiomas with relatively low incidence of complications. Patients with improved vision to good functional level had a better preoperative visual status.

Outcomes and quality of life assessment in patients undergoing endoscopic surgery for pituitary adenomas

The endoscopic technique is increasingly being used for the resection of pituitary adenomas. Its efficacy and safety have been generally accepted, but its impact on the quality of life of the patients treated has not been previously addressed. Most of the studies assessing the quality of life after long-term cure of pituitary adenomas suggest a significantly impaired quality of life (QoL) in all subgroups of pituitary tumours. In our study we analyse QoL data following endoscopic surgery, and attempt comparisons with normative and data from standard approaches. The validated health questionnaire SF-36 was sent to 80 patients who had undergone pure endoscopic resection of a pituitary adenoma. Fifty-four patients returned the completed questionnaire. Outcomes were compared with normative data for the Short Form-36 (SF-36) Heath survey for the general Canadian population. We also compared the results amongst different types of adenomas. We attempted a comparison to previous studies on quality of life for patients who underwent conventional trans-sphenoidal surgery. Our study suggests only minimal impairment of quality of life in patients after successful treatment of pituitary adenomas using the endoscopic approach. There were only very few differences in the perceived quality of life within the different subgroups of adenomas. There was a trend to improved scores in the endoscopic group compared with previous studies in patients treated by conventional approaches. Whilst our data suggest minimal impact on the quality of life for patients after endoscopic removal of pituitary adenomas, further studies with larger number of patients and longer follow-up are required to encourage this finding.

Postoperative assessment of clipped aneurysms with 64-slice computerized tomography angiography.

BACKGROUNDMultidetector computerized tomography angiography (MDCTA) is now a widely accepted technique for the management of intracranial aneurysms. OBJECTIVETo evaluate its accuracy for the postoperative assessment of clipped intracranial aneurysms. METHODSWe analyzed a consecutive series of 31 patients that underwent direct surgical clipping procedures of 38 aneurysms. A 64 slice MDCT scanner (Aquilion 64, Toshiba) was used and results were compared with digital subtraction angiographies (DSA). Two independent neuroradiologists analyzed the following data: examination quality, artifacts, aneurysm remnant, and patency of collateral branches. Interobserver agreement, sensitivity, and specificity were calculated. RESULTSSeventy-nine percent of the aneurysms were located in the anterior circulation. Significant artifacts were found with multiple and cobalt-alloy clips. According to DSA, remnants >2 mm were found in 21% of the cases, and 2 patients had one collateral branch occluded. Sensitivity and specificity of 64-MDCTA for the detection of aneurysm remnants were 50% and 100%, respectively. Sensitivity and specificity of 64-MDCTA for the detection of a significant remnant (>2 mm) and the detection of the occlusion of a collateral branch were, respectively, 67% and 100% and 50% and 100%. No relationship was found with the location, type, shape, size, or number of clips, but missed remnants tended to be larger with cobalt-alloy clips. CONCLUSIONS64-MDCTA is a valuable technique to assess the presence of a significant postoperative remnant in single titanium clip application cases and might be useful for long-term follow-up. DSA remains the most accurate postoperative radiological examination.

Direct imaging of the distal dural ring and paraclinoid internal carotid artery aneurysms with high-resolution T2 turbo-spin echo technique at 3-T magnetic resonance imaging.

OBJECTIVETo evaluate the feasibility of the direct visualization of the distal dural ring (DDR) and adjacent anatomic structures in patients with paraclinoid internal carotid artery aneurysms at 3-T magnetic resonance imaging (MRI). METHODSSix consecutive patients (1 man, 5 women; mean age, 45.5 years; age range, 34–51 years) who underwent a 3-T MRI examination for the evaluation of 7 paraclinoid carotid artery aneurysms were reviewed retrospectively. MRI scans were acquired using a T2 turbo-spin echo sequence with 2-mm thickness without gap on the coronal plane perpendicular to the diaphragma sellae. Identifications of the DDR, adjacent regional anatomic landmarks, and paraclinoid aneurysms were analyzed. The locations of the paraclinoid aneurysms were categorized into intradural (aneurysm neck and sac located above the DDR), transdural (aneurysm neck or sac were straddling the DDR), and extradural (aneurysm neck and sac located below the DDR). Interstudy agreement between computed tomographic angiography and 3-T MRI for the anatomic location of the paraclinoid aneurysms was assessed in 6 patients who underwent both examinations. RESULTSIn all cases, the DDR was clearly identified and the relationship between the DDR and the paraclinoid aneurysm was successfully determined on 3-T MRI. The aneurysm locations determined with 3-T MRI were 4 intradural and 3 extradural. A comparison between computed tomographic angiography and 3-T MRI revealed discordant anatomic locations in 3 aneurysms (3 of 6, 50%). CONCLUSIONDirect visualization of the DDR as well as precise evaluation of paraclinoid aneurysm location with high-resolution 3-T MRI is possible. This study shows that high-resolution 3-T MRI is an important means to determine the appropriate management for patients with paraclinoid aneurysms.

Assessment of extracranial–intracranial bypass patency with 64-slice multidetector computerized tomography angiography

IntroductionExtracranial–intracranial (EC/IC) bypass is a useful procedure for the treatment of cerebral vascular insufficiency or complex aneurysms. We explored the role of multidetector computed tomography angiography (MDCTA), instead of digital subtraction angiography (DSA), for the postoperative assessment of EC/IC bypass patency.MethodsWe retrospectively analyzed a consecutive series of 21 MDCTAs from 17 patients that underwent 25 direct or indirect EC/IC bypass procedures between April 2003 and November 2007. Conventional DSA was available for comparison in 13 cases. MDCTA used a 64-slice MDCT scanner (Aquilion 64, Toshiba). The proximal and distal patencies were analyzed independently on MDCTA and DSA by a neuroradiologist and a neurosurgeon. The bypass was considered patent when the entire donor vessel was opacified without discontinuity from proximal to distal ends and was visibly in contact with the recipient vessel.ResultsMDCTA depicted the patency status in every patient. Bypasses were patent in 22 cases, stenosed in one, and occluded in two. DSA always confirmed the results of the MDCTA (sensitivityu2009=u2009100%, 95% CIu2009=u20090.655–1.0; specificity 100%, 95% CIu2009=u20090.05–1.0).ConclusionsMDCTA is a non-invasive and accurate exam to assess the postoperative EC/IC bypass patency and is a promising technique in routine follow-up.

Vestibular Schwannomas presenting with haemorrhage: Clinical presentation and histopathological evaluation of an unusual entity

Gross intratumoral haemorrhage is rare in vestibular schwannomas. The authors describe the clinical features of this entity in 6 patients, the histopathologic findings in 5 of them, and discuss possible factors predisposing to haemorrhage in these tumors. Detailed radiological and histopathological evaluation identified two factors which may be associated with higher likelihood of haemorrhage, namely preoperative radiation therapy and vascular abnormalities. Tumor size may not be a major risk factor for haemorrhage. Good outcomes can be achieved with microsurgical management. The histological features presented here differ clearly from findings in previously published case reports.

Coincidence vs cause: cure in three glioblastoma patients treated with brachytherapy.

BACKGROUNDnVery long term survival after diagnosis of malignant glioma has been described in individual case reports. Survival of more than 10 years is extremely rare, especially when identified in 3 out of 71 patients assigned to one arm of a randomized controlled trial.nnnPATIENTSnThree patients survived 11, 16, and 18 years following the diagnosis of glioblastoma and treatment with surgery, conventional fractionated radiation, and high-activity iodine-125 boost brachytherapy as part of a randomized controlled trial.nnnCONCLUSIONnDespite this apparent cause and effect relationship, statistical analysis shows no relationship between these cures and treatment with brachytherapy. Cure of glioblastoma remains rare.