Correlation between the Position of the Pituitary Stalk as Determined by Diffusion Tensor Imaging and Its Location as Determined at the Time of Surgical Resection of Pituitary Adenomas

Objective@#: An important factor during pituitary adenoma surgery is to preserve pituitary stalk (PS) as this plays a role in reduction of the risk of postoperative diabetes insipidus. The hypothalamic-hypophyseal tract (HHT) projects through the PS to the posterior pituitary gland. To reconstruct white matter fiber pathways, methods like diffusion tensor imaging (DTI) tractography have been widely used. In this report we attempted to predict the position of PS using DTI tractography and to assess its intraoperative correlation during surgery of pituitary adenomas. @*Methods@#: DTI tractography was used to tract the HHT in nine patients before craniotomy for pituitary adenomas. The DTI location of the HHT was compared with the PS position identified at the time of surgery. DTI fiber tracking was carried out in nine patients prior to the planned craniotomy for pituitary adenomas. In one patient, the PS could not be identified during the surgery. In the other eight patients, a comparison was made between the location of the HHT identified by DTI and the position of the PS visualized at the time of surgery. @*Results@#: The position of the HHT identified by DTI showed consistency with the intraoperative position of the PS in seven patients (88.9% concordance). @*Conclusion@#: This study shows that DTI can identify the position of the HHT and thus the position of the PS with a high degree of reliability.

Trans-extradural approach to resect trigeminal schwannomas involving the cavernous sinus region / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the techniques and effect of extradural approach for the resection of trigeminal schwannomas involving the cavernous sinus.</p><p><b>METHODS</b>Twenty-three patients (range 26-63 years, mean age 46.2 years) with trigeminal schwannomas involving the cavernous sinus treated by middle fossa extradural approach were retrospectively analyzed. Frontotemporal orbitozygomatic extradural approach was performed in 2 patients. Frontotemporal zygomatic extradural approach was carried out in 21 patients. The first follow-up visit was on the 3rd month after surgery, and if residual was observed on enhanced MRI, then the patient was followed up every 6 months; otherwise, the patient was followed up every 8-12 months.</p><p><b>RESULTS</b>The length of hospital stay after surgery was 7-13 days (mean 8.5 days). Two tumors originated from the ophthalmic branch, 2 from the maxillary branch, 5 from the mandibular branch and 14 from the gasserian ganglion. Total resection was achieved in 21 of the 23 patients (91.3%) and subtotal resection in the other 2 patients. All the patients were followed up from 3 months to 4 years. Median follow-up time was 19 months. The most common symptom was facial hypoesthesia, occurring in 18 patients. This symptom improved in 10 patients and worsened in 8 patients after surgery. New postoperative facial hypoesthesia was observed in 2 patients. Facial pain was observed in 3 patients and subsided after surgery. Two patients had loss of hearing, this symptom improved in 1 patient and worsened in 1 patient after surgery. Diplopia was observed in 6 patients. In 1 of these 6 patients, diplopia resulted from palsy of the oculomotor nerve. In the other 5 patients, diplopia resulted from palsy of the abducens nerve. This symptom improved postoperatively in all these 6 patients. New postoperative atrophy of the temporalis muscle was observed in 3 patients. There was no operation-related mortality. Tumor recurrence was only found in 1 patient after 24 months and was treated by Gamma knife.</p><p><b>CONCLUSIONS</b>The middle fossa extradural approach may be an ideal option for the resection of trigeminal schwannomas involving the cavernous sinus. This approach produces no further impairment, less complication, and is less likely to injured the trigeminal nerve, abducens nerve, trochlear nerve and internal carotid artery.</p>

Functional neuro-navigation and intraoperative magnetic resonance imaging for the resection of gliomas involving eloquent language structures / 中华外科杂志

<p><b>OBJECTIVES</b>To explore the clinical value of functional neuro-navigation and high-field-strength intraoperative magnetic resonance imaging (iMRI) for the resection of intracerebral gliomas involving eloquent language structures.</p><p><b>METHODS</b>From April 2009 to April 2010, 48 patients with intracerebral gliomas involving eloquent language structures, were operated with functional neuro-navigation and iMRI. Blood oxygen level dependent functional MRI (BOLD-fMRI) was used to depict both Broca and Wernicke cortex, while diffusion tensor imaging (DTI) based fiber tracking was used to delineate arcuate fasciculus. The reconstructed language structures were integrated into a navigation system, so that intra-operative microscopic-based functional neuro-navigation could be achieved. iMRI was used to update the images for both language structures and residual tumors. All patients were evaluated for language function pre-operatively and post-operatively upon short-term and long-term follow-up.</p><p><b>RESULTS</b>In all patients, functional neuro-navigation and iMRI were successfully achieved. In 38 cases (79.2%), gross total resection was accomplished, while in the rest 10 cases (20.8%), subtotal resection was achieved. Only 1 case (2.1%) developed long-term (more than 3 months) new language function deficits at post-operative follow-up. No peri-operative mortality was recorded.</p><p><b>CONCLUSIONS</b>With functional neuro-navigation and iMRI, the eloquent structures for language can be precisely located, while the resection size can be accurately evaluated intra-operatively. This technique is safe and helpful for preservation of language function.</p>

Implementation and preliminary experience of high-field intraoperative magnetic resonance imaging in the endoscopic chordoma operation with transsphenoidal or transoral approach / 中华外科杂志

<p><b>OBJECTIVE</b>To review the preliminary clinical experience with high-field-strength intra-operative magnetic resonance imaging (iMRI) in the endoscopic chordoma operation with transsphenoidal or transoral approach.</p><p><b>METHODS</b>From January 2009 to December 2010, 23 patients [range, 29 - 64 years, mean age (42 ± 3) years] of chordoma were operated with endoscopic transsphenoidal or transoral approach and examined intraoperatively with a movable 1.5 T iMRI magnet. Tumor size range was 2.0 - 5.7 cm, mean (3.5 ± 0.8) cm. A navigation system based on iMRI was used in 20 cases.</p><p><b>RESULTS</b>iMRI scan were performed in each operation from 1 time to 5 times. Neuronavigation system were used in 20 operations and the data renewed in 12 cases by the information from iMRI. In 15 of 23 patients, iMRI had revealed residual lesions and resulted in 12 cases further treatment, eventually, 9 tumors were totally removed and 3 tumors were further removed. The ratio of total removal tumor was enhanced to 73.9% (17/23) from 34.8% (8/23). Among 15 cases of partial chordoma removal detected by scanning in operation, 9 were huge chordoma. The residual of huge chordoma detected by scanning in operation was 9/11, and other chordoma contributed to 6/12. There were no iMRI related safety issue or accident recorded in this study.</p><p><b>CONCLUSIONS</b>High-field-strength iMRI provide high-quality images of tumor resection that allows intraoperative modification of the surgical strategy. Combined with the navigation system, iMRI is helpful to maximize the resection of the chordoma and benefit for the safety of endoscopic operation.</p>

High-field intraoperative magnetic resonance imaging suite with neuronavigation system: implementation and preliminary experience in the pituitary adenoma operation with transsphenoidal approach / 中华外科杂志

<p><b>OBJECTIVES</b>To review the preliminary clinical experience with high-field-strength intraoperative magnetic resonance imaging (iMRI) suite with neuronavigation system in the pituitary adenoma operation with transsphenoidal approach.</p><p><b>METHODS</b>From March 2009 to December 2010, 31 patients [range, 29 - 76 years, mean age (47 ± 11) years]of pituitary adenoma were operated with transsphenoidal approach and intraoperatively with a movable 1.5 T high-field-strength iMRI suite in combination with neuronavigation system. Tumor size was 1.8 - 7.3 cm, mean (3.5 ± 1.2) cm. Twenty-five cases were non-functional pituitary adenoma, 4 cases were prolactin-secreting pituitary adenoma, 2 cases were growth hormone-secreting pituitary adenoma. Thirty patients' resection with transnasal transsphenoidal approach were performed, one patient with transoral transsphenoidal approach was performed.</p><p><b>RESULTS</b>In 12 cases of 30 patients who planed to totally remove tumor, iMRI had revealed residual lesions and resulted in the change of the surgical strategy, 2 invasive cavernous sinus cases no further resection of the tumor because of internal carotid artery encasement, the other 10 cases resected further, eventually. Finally, 8 cases were totally removed. The ratio of total removal tumor was enhanced to 86.7% (26/30) from 60.0% (18/30). There was no perioperative mortality.</p><p><b>CONCLUSIONS</b>High-field-strength iMRI suite with neuronavigation system provides valuable information of tumor resection that allows intraoperative modification of the surgical strategy. It could be very helpful to maximize the resection of the pituitary adenoma and minimize the injury to neurological function.</p>

Pure endoscopic endonasal transsphenoidal approach for 375 pituitary adenomas / 中华外科杂志

<p><b>OBJECTIVE</b>To describe the experience with surgical treatment of pituitary adenomas via a fully transnasal endoscopic approach.</p><p><b>METHODS</b>Clinical records of 375 cases with pituitary adenomas underwent pure endoscopic operations between December 2006 and December 2009 were carefully assembled. Among 375 pure endoscopic operations of pituitary adenomas, 201 cases were nonfunctional adenomas and 174 cases were functional adenomas. There were 27 giant pituitary adenomas (7.2%) and 41 pituitary adenoma invaded cavernous sinus (10.9%). Intraoperative 1.5 T MRI and neuro-navigation system were used during some operations. The postoperative and follow-up data of patients were analyzed.</p><p><b>RESULTS</b>There were 234 (79.3%) cases of total resection, 56 (19.0%) cases of subtotal resection, 5 (1.7%) cases of partial resection. Sixty-eight patients had vision improved in 73 patients with vision decreasing before operation. Sixty-eight (77.3%) patients got normal endocrine in 88 hyper-prolactin patient. Fifty-five (84.1%) patients got normal growth hormone in 63 patients with somatotrophinomas. Eighteen (78.2%) patients got normal in 23 patients with corticotrophinoma. These was no death case in this group. One case (0.3%) suffered post-operative coma. Transient decreasing of vision occurred in 2 cases (0.5%). Transient palsy of oculomotor nerve or abducens nerve occurred in 7 cases of operations involved cavernous sinus. Three (0.8%) patients had cerebral meningitis. Two patients (0.5%) suffered from cerebrospinal fluid leak but none underwent operation to repair. Fourteen patients (3.7%) had transient diabetes insipidus. Six patients (1.6%) had nose bleeding.</p><p><b>CONCLUSIONS</b>Trans-nasal endoscopy provides a new device for operation of pituitary adenomas which is effective and safe. Comparing with microscope, endoscopic visual field is clearer, closer and wider.</p>