XXIX Reunión da Sociedade Galega de Neuroloxía. Comunicaciones: Vigo, Pontevedra, 8-9 de mayo de 2015 / XXIX Reunión da Sociedade Galega de Neuroloxía. Communications

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Transsphenoidal surgery using a high definition video telescope for pituitary adenomas in dogs with pituitary dependent hypercortisolism: methods and results.

OBJECTIVE: To (1) establish a technique for transsphenoidal removal of pituitary adenomas in dogs with pituitary dependent hypercortisolism (PDH) using a high definition video telescope, and (2) report initial outcomes. STUDY DESIGN: Prospective case series. ANIMALS: Dogs with pituitary dependent hypercortisolism (PDH; n = 26) with suprasellar masses. METHODS: Pituitary tumors were removed using a modification of a transoral transsphenoidal approach. Surgery was observed using a high definition video telescope (VITOM™) and localization of the sella was performed by drilling pilot holes in the basisphenoid bone followed by computed tomography (CT). RESULTS: Dogs had PDH confirmed by urinary cortisol to creatinine ratio (UCCR) and endogenous ACTH assays, and tumors confirmed by MRI. There were no postoperative cerebrospinal fluid leaks, wound dehiscence, or surgical site infections. Overall postoperative mortality was 19% with no mortality observed in the last 16 dogs, indicating an initial "learning curve" followed by good surgical results. All dogs that survived the immediate postoperative period (1 week) returned to their owners in good health, on hormonal replacement therapy. Follow-up ranged from 3 to 36 months. Sustained tumor control and hormonal remission based on normalized ACTH and UCCR measurements were observed in 20/21 (95%) dogs at 1-year follow-up. CONCLUSIONS: Modifications of a trans-oral transsphenoidal technique for surgical removal of pituitary tumors provides a safe and effective strategy for long-term remission of PDH with acceptable morbidity and mortality.

[Clinical application of a new titanium clip applier in transsphenoidal surgery].

OBJECTIVE: To explore the efficacy and safety of a new titanium clip applier in transsphenoidal surgery for the A specially devised surgery instrument was developed and effectively applied in the management of intercavernous sinus hemorrhage and cerebrospinal fluid (CSF) leakage in transsphenoidal surgery. METHODS: A total of 34 consecutive patients with pituiary adenoma underwent transsphenoidal surgery via a new deep pistol-shaped clip applier versus titanium clip. It was 21 cm long with a rectangular forepart. All patients were evaluated clinically and radiologically at 24 months and magnetic resonance imaging (MRI) was performed at Months 3-18 postoperation. RESULTS: The application of such a new clip applier was effective. No operation was terminated due to ineffective hemorrhage, postoperative CSF leakage or related complications. Postoperative imaging studies revealed no significant evidence of clip artifact. CONCLUSION: The technique of hemostasis and leakage clogging with such a new clip applier is safer, faster and more reliable than its conventional counterpart in achieving dural closure and intercavernous sinus hemostasis.

[Technical peculiarities of trans-sphenoidal surgical interventions for prolactin-secreting pituitary adenoma].

The results of treatment of 84 patients, operated on for prolactinoma, using transsphenoidal access, were analyzed. All the stages of transsphenoidal surgical treatment are depicted in details, beginning from the patient's position on operative table and distribution of the devices in operating room and up to performance of nasal tamponade. There was established the dependence of the surgical intervention radicalism from the tumor topographo-histological peculiarities and from the earlier conducted treatment as well.

Combined simultaneous transcranial and transsphenoidal resection of large-to-giant pituitary adenomas.

BACKGROUND: While large-to-giant pituitary adenomas (PAs) may be safely removed by experienced surgeons through a single route, the procedure is technically challenging. We present the outcome of a simultaneous combined transcranial and transsphenoidal approach and discuss its applications. METHODS: A retrospective review was conducted on 12 consecutive patients. Surgical complications, visual and endocrinological functions, and tumour control were reviewed. RESULTS: There were four men and eight women, with a mean age of 47.6 years. All but one patient had non-functioning PAs. The mean tumour height was 4.1 cm (range: 2.3-5.5). The predominant presenting symptoms were visual field loss in eight patients, headache in three patients and mental confusion in one patient. There was no operative mortality. Post-operative cerebrospinal fluid leakage occurred in one patient. Five of the eight patients who presented with visual field loss achieved full recovery, and three had partial improvement. Two patients developed permanent diabetes insipidus after surgery. Panhypopituitarism occurred in one patient. Gross total removal (GTR) was achieved in five, and subtotal removal (STR) in seven patients. Seven patients received post-operative external irradiation. All patients who had GTR remained tumour-free and all those with STR had stable diseases after a mean follow-up period of 53.1 months (range: 14.1-92.1). CONCLUSION: The simultaneous 'above and below' approach is a safe and effective surgical strategy for large-to-giant PAs, particularly when expertise in endoscopic transsphenoidal surgery is unavailable. Its use, however, should be limited to a carefully selected group of patients, and tailored to individual user's expertise and experience.

Results of endoscopic transsphenoidal pituitary surgery in 40 patients with a growth hormone-secreting macroadenoma.

OBJECTIVE: Transsphenoidal pituitary surgery (TS) is the primary treatment of choice for patients with acromegaly. Macroadenomas (>1 cm) are more difficult to resect than microadenomas (remission rate ± 50% compared to ± 90%). Besides the conventional microscopic TS, the more recently introduced endoscopic technique is nowadays frequently used. However, no large series reporting on its results have yet been published. We evaluated the outcome of endoscopic TS in 40 patients with a growth hormone (GH)-secreting macroadenoma treated in our hospital between 1998 and 2007. METHODS: Medical records were retrospectively reviewed. Remission was defined as disappearance of clinical symptoms of acromegaly, normal serum insulin-like growth factor-1 levels (≤2 SD) and serum GH levels suppressed to <2 mU/l after an oral glucose tolerance test within the first 4 months after TS. RESULTS: In four patients TS aimed at debulking of the tumour. In the remaining 36 patients, remission was achieved in 20 patients. In the first 5 years remission was achieved in 6 out of 18 patients (33%) compared to 14 out of 22 patients (63%) in the following 5 years (p = 0.06). Thirteen patients had a mild perioperative complication. Before TS 15 patients received hormonal substitution therapy compared to 12 patients (33%) after TS. CONCLUSION: Endoscopic TS is a good primary therapeutic option for patients with a GH-secreting macroadenoma, resulting in a remission rate of up to 63% in experienced hands. This technique can potentially improve the outcome of TS in these patients.

Functional impairments caused by chiasma syndromes prior to and following transsphenoidal pituitary adenoma surgery.

PURPOSE: To describe the functional impairment caused by chiasma syndromes (CS) prior to and following transsphenoidal pituitary adenoma surgery. METHODS: Pertinent data of a successive series of patients operated transsphenoidally for the first time for pituitary adenoma were retrospectively analyzed. The degree of functional impairment caused by the impairment of vision was quantified according to the resulting degree of disability (DOD). A DOD of > or =30 is considered substantial. RESULTS: None of the 197 of 304 (64.9%) patients without preoperative chiasma syndrome (CS) experienced postoperative worsening of their visual acuity or their visual fields. Thus, no change of their vision-related DOD (V-DOD) did occur. One hundred and seven (35.1%) of the patients presented preoperatively with CS. Postoperatively, 42.9% of the CS remitted completely, 38.3% improved, 11.2% remained unchanged, and 7.4% worsened. Accordingly, the median V-DOD improved significantly from 30 (0; 100) to 0 (0; 100). The prevalence of patients with V-DOD > or =30 dropped significantly from 51.4% preoperatively to 16.4% postoperatively. Postoperatively, the median V-DOD improved significantly up to 3 months postoperatively. Thereafter, no further significant changes occurred. However, in patients with preoperative CS, the median V-DOD as well as the prevalence of patients with a V-DOD > or =30 remained postoperatively significantly higher compared to patients without preoperative CS. CONCLUSIONS: Visual impairments due to CS frequently caused substantial DOD preoperatively. Postoperatively, the median degree of V-DOD as well as the prevalence of substantial V-DOD improved significantly. However, in patients with preoperative CS, V-DOD remained postoperatively significantly higher than V-DOD of patients without preoperative CS.

Feasibility of Polestar N20, an ultra-low-field intraoperative magnetic resonance imaging system in resection control of pituitary macroadenomas: lessons learned from the first 40 cases.

OBJECTIVE: To evaluate the feasibility of PoleStar N20 (Medtronic Surgical Navigation Technologies, Louisville, KY), an ultra-low-field intraoperative magnetic resonance imaging (iMRI) system during resection control of pituitary macroadenomas and to compare intraoperative images with postoperative 1.5-T MRI images obtained 3 months after the procedure. METHODS: Forty patients with a pituitary macroadenoma (mean size, 26.9 +/- 9.1 mm) underwent a surgical procedure to remove the tumor. The iMRI system was implemented in a standardized microsurgical procedure (endonasal, transseptal, transsphenoidal approach) using standard microsurgical instruments. Intraoperative imaging was performed for tumor visualization/navigation and resection control. If an accessible tumor remnant was suspected, surgery was continued for reexploration and, if necessary, continued resection. Total anesthesia time and operation time were compared with a historical cohort of 100 patients who underwent a surgical procedure on pituitary adenomas without iMRI. Sensitivity and specificity of the iMRI to detect residual tumor tissue was assessed in 33 patients (82.5%) after comparison with standard postoperative 1.5-T MRI 3 months after the procedure. RESULTS: Preoperative tumor visualization with the ultra-low-field iMRI showed a very good congruency with the preoperative 1.5-T MRI scans. A three-dimensional reconstruction of the coronal scan enabled the surgeon to safely approach the tumor using the integrated navigation system. In seven patients (17.5%), iMRI resection control showed accessible residual tumors leading to further resection. After tumor resection, the final iMRI scan documented adequate decompression of the optic pathway in all patients. Implementation of iMRI led to a significant increase of anesthesia time (246.0 +/- 50.7 versus 163.4 +/- 41.2 min) and operation time (116.9 +/- 43.9 versus 78.2 +/- 33.0 min; P < 0.05, t test). Sensitivity of the iMRI was 88.9, 85.7, 93.3, and 100% for the suprasellar, intrasellar, and right and left parasellar regions, respectively, and the specificity was 90.5% in the suprasellar and 100% in the intra- and parasellar regions on both sides. In four patients, the intraoperative interpretation of iMRI was equivocal; thus, it was difficult to distinguish between very small tumor remnants and perioperative changes. CONCLUSION: Ultra-low-field 0.15-T iMRI is a safe, helpful, and feasible tool for navigation and tumor resection control in patients with pituitary macroadenomas. Total anesthesia and operation times are prolonged, but iMRI adequately documents the extent of tumor resection. In this series, the PoleStar system increased the rate of resection without disrupting the neurosurgical workflow.

[Methods of the endoscopic endonasal transsphenoidal adenomectomy].

This paper provides the practical part of a procedure for endoscopic endonasal transsphenoidal resection of pituitary tumors. The authors have presently gained experience with about 400 endoscopic endonasal transsphenoidal operations. The advantages of endoscopic surgery include the wide vision field of an operative site under good illumination. The endoscopic intervention provides a possibility of extracting not only endo-, but also paracellular portions of a tumor under direct visual control, which can be rarely done during a standard microscopic transnasal operation. The paper gives recommendations on the equipment of an operating suite and anesthetic maintenance. It also describes surgical stages and postoperative management of patients.

Speculum opening in transsphenoidal surgery.

OBJECTIVE: To assess the extent to which the transsphenoidal speculum can be safely opened at the face of and within the sphenoid sinus without risking damage to the optic nerves in the optic canals and at the orbital apex and the nerves coursing adjacent the walls of the sphenoid sinus. METHODS: The distance was measured between the optic nerves at the level of the anterior wall of the sphenoid sinus and 0.5 and 1.0 cm within the sinus. In addition, the distance between the middle turbinates and the contralateral optic canals was assessed because this turbinate is the largest structure blocking access to the sphenoid sinus in the transsphenoidal approach and tends to force the speculum away from the midline and toward the optic nerve in the contralateral side of the approach. RESULTS: Opening the transsphenoidal speculum at the anterior wall of the sphenoid sinus beyond 2.5 centimeters carries some risk of damaging the optic nerves and this distance narrows when the speculum opening is positioned inside the sphenoid sinus. Displacement of the speculum to one side by the middle turbinate places the speculum near the contralateral optic nerve and may be associated with optic nerve injury with lesser degrees of speculum opening. CONCLUSIONS: Careful attention should be directed to avoiding excessive opening of the transsphenoidal speculum at the anterior face of the sphenoid or within the sphenoid sinus.

[Development of new surgical tools, Q-PAL and HP-Jet for endoscopy only used unilateral transnasal approach for pituitary adenomas].

UNLABELLED: The aim of this study is to present surgical techniques and results of endoscope-assisted transnasal approach (TNA) for pituitary adenomas. It is a new alternative for Hardy's surgery (TSS). We performed TNA assisted by only endoscope through single nostril. METHOD: We enter the sphenoid sinus directly through the natural ostium and ablate neither the nasal septum nor the vomer bone. We found the hardest problem of this method resides in its deep and narrow working space which obstructs usage of two tools at same time. To overcome this problem we developed two surgical tools, Q-PAL and HP-Jet. Q-PAL is combination of PAL and suction. We place flexible PAL wire electrode through suction tube so as PAL tip protrudes from suction tip. This eliminates coagulation smoke which otherwise disturbs surgeons view. HP-Jet is a combination of a suction tool and an irrigator. The irrigator is connected to syringe containing saline. Saline is injected manually from tip bursting up tumor tissue with its jet pressure. It is safe and effective instrument suitable for extirpation of rather fragile tissue like adenomas existing in deep and blind spaces. CASES: Since 2004 we have operated on 16 patients using endoscopic TNA. Eight were non-functioning adenomas, and 8 functioning. RESULTS: Results of surgery were compared with those of 10 cases operated by TSS. More than 70% removal of adenoma was achieved in 75% of cases with TNA, but in only 71% with TSS. Postoperative CSF rhinorrhea was seen in one case. Four cases showed postsurgical transient diabetes insipidus. We had no case with postsurgical infection. With the help of instruments having multiple functions in single probe such as Q-PAL and HP-Jet, we can execute endoscopic TNA more smoothly and more safely.

Technique for performance and evaluation of parapharyngeal hypophysectomy in mice.

Mice at our institution were hypophysectomized to evaluate the effects of growth hormone on the expression of a transfected human factor IX gene. The hypophysectomy was performed in-house by using a parapharyngeal approach modified from previously published surgical techniques. Modifications included: 1) choice of ketamine-xylazine and isoflurane for anesthesia, with butorphanol for postoperative analgesia; 2) use of a V-trough for positioning mice correctly and consistently; 3) selection of increasing sizes of dental burrs to create a foramen in the cranial base through which the pituitary gland was removed; and 4) disuse of a tracheotomy for airway patency. In addition, verification of successful gland removal was assessed by measuring major urinary protein (MUP) in the urine; presence of MUP indicated incomplete hypophysectomy. This assessment enabled antemortem determination of surgical success by using a single urine collection. Each of these modifications contributed to the success of the surgical procedure. We had a safe and reliable anesthetic regimen, consistent positioning of the surgical patient, and smooth and rapid penetration of the cranium. In our experience, the tracheotomy described in previous techniques was unnecessary, as the mice tolerated brief periods of apnea (approximately 5 sec maximum) while the trachea was retracted. Here we seek to provide details that will assist those interested in learning this technique and that will reduce the number of mice needed for practice. Other applications include a method of evaluating the production of growth hormone without euthanizing the animal.

Functional hypophysectomy simply by neck-strangulation in the rat: applications for ACTH and LH assays.

The classical methods for hypophysectomy require a long training-period and at the end of each experiment, it is required to check any undue remnant of the hypophyseal tissue in the sella turcica, and there must be exclusion of such datum with the remnant from the experimental group. The present method for functional hypophysectomy by neck-strangulation in the rat is very simple to perform so that even an experimenter with little experience can become easily accustomed to the technique and obtain a number of functionally hypophysectomized preparations at any time he intends, with no need to check the remnant. The cerebral blood circulation of vertebrally dislocated rats was immediately intercepted by means of neck-strangulation and artificially respired. Fifteen minutes after intravenous injection of ACTH (0.1 - 3.2 mU/rat) or LH (312.5 - 2500 ng/rat), blood was sampled from the vena cava, and sera were examined for corticosterone or testosterone by radioimmunoassay. A linear dose-response relationship was obtained within a dose range of 0.2 - 1.6 mU/rat of ACTH and 312.5 - 1250 ng/rat of LH. In the ACTH assay, parapharyngeally hypophysectomized rats were compared. It was found that the sensitivity of functionally hypophysectomized preparations was 2.72 times higher than that of the parapharyngeally hypophysectomized rats.

Electrorhinomanometric evaluation of nasal functions in transseptal-transsphenoidal hypophysectomy.

OBJECTIVE: The prospective study in 23 patients, who were undergone transseptal-transsphenoidal hypophysectomy, underlines the rhinologic aspects of this technique. MATERIALS AND METHODS: Preoperative and postoperative subjective complaints were compared, postoperative nasal respiratory functions were evaluated by means of electrohinomanometry. RESULTS: Nasal respiratory functions were preserved postoperatively in the patients with normal preoperative nasal anatomy (no statistical difference); while, in patients with obstructive deviation of the nasal septum, an improvement in nasal respiratory functions were noted as a result of simultaneously performed septoplasty (p < 0.01). CONCLUSION: Our results emphasize the importance of the collaboration of otorhinolaryngology and neurosurgery teams for the sake of postoperative nasal functions.

[Technical aspects and surgical strategy for removal of corticotroph pituitary adenoma]. / Aspects techniques et conduite de l'exérèse de l'adénome hypophysaire corticotrope.

The development of transsphenoidal microsurgery and the refinement of endocrinological and radiological diagnostic procedures have afforded therapeutic options appropriate for each individual case in patients with pituitary-dependent hypercortisolism. Compared with other secreting pituitary tumors, the corticotroph adenoma seems to be the most biologically active tumor. Clinical evidence of hypercortisolism mainly occurs at an early stage of tumor growth when the tumor is very small, below the detection threshold of modern imaging techniques. While the treatment of large tumors remains difficult due to the non-discrete boundary lines of the tumor and extension or invasion, surgical removal of very tiny tumors requires reliable preoperative or peroperative identification in order to achieve total tumor resection for clinical remission and pituitary preservation to prevent hypopituitarism. We reviewed all the current surgical techniques or clever surgical procedures used to achieve both goals with the lowest complication rate. We report here the state-of-the-art of surgical management of corticotroph pituitary adenoma focusing on preoperative radiological and biological data required for performing guided intrasellar surgical exploration and reliable tumor identification. Different technical aspects of the nasosphenoidal approaches are reported as well as the modified transdiaphragmatic or transtubercular transcisternal approaches to tumors in a suprasellar localization or lying along the pituitary stalk. The advantages of minimally invasive surgical techniques such as intrasellar endoscopic surgery are discussed. Adapted surgical techniques for second transnasal surgery indicated for recurrent tumors are described. Guidelines are given for peroperative tumor identification with macroscopic assessment or histological control with frozen section biopsies. Different techniques for tumor removal are discussed from selective microadenomectomy to enlarged pituitary resection and total hypophysectomy. Methods for preoperative guidance of total tumor removal are proposed including histological or biological assessment of normal adjacent pituitary tissue. the strategy of surgical intrasellar exploration and tumor resection is outlined using a set of algorithms. The first is devoted to positive preoperative documentation of the tumor. The second is proposed for the surgical scenario where there is no preoperative MRI evidence of the tumor. Special strategies are discussed for ectopic adenoma or multiple tumors. Revision surgical management after surgical failure or tumor recurrence is described. Special guidelines for surgical treatment of large clinically silent corticotroph macroadenomas are given with emphasis on the high risk of recurrence in comparison with other silent pituitary tumors such as gonadotroph or immunonegative adenomas.

Transcolumellar approach in transsphenoidal pituitary surgery for patients with small nostril.

OBJECTIVE: Sublabial approach has been widely used as the standard technique for transsphenoidal pituitary surgery. But it has several possible drawbacks, such as; postoperative flat nose deformity, hypesthesia of upper gum, and feeding difficulty until 2 to 3 weeks after surgery. As an alternative, an endonasal approach was adopted for patients who had large nostrils, such as white or acromegalic patients. In patients with small nostrils, especially oriental people, it requires an additional tension release incision that leaves a definitely visible scar at the base of nose. STUDY DESIGN: We applied the transcolumellar approach, which modified the external rhinoplasty approach on the 136 cases of transsphenoidal pituitary surgery that were performed from 1994 to June 1999. RESULTS: In all patients, we found we could reach the anterior portion of nasal septum in 7 to 8 mm in depth from the skin surface and eliminate the disadvantages of sublabial and endonasal approach. Also, this method can markedly reduce the surgical dissection time and blood loss. CONCLUSIONS: We concluded that this technique was relatively simple and more than adequate in most transsphenoidal pituitary surgery, even in patients with small nostrils.

Intraoperative magnetic resonance imaging during transsphenoidal surgery.

OBJECT: The aim of this study was to evaluate whether intraoperative magnetic resonance (MR) imaging can increase the efficacy of transsphenoidal microsurgery, primarily in non-hormone-secreting intra- and suprasellar pituitary macroadenomas. METHODS: Intraoperative imaging was performed using a 0.2-tesla MR imager, which was located in a specially designed operating room. The patient was placed supine on the sliding table of the MR imager, with the head placed near the 5-gauss line. A standard flexible coil was placed around the patient's forehead. Microsurgery was performed using MR-compatible instruments. Image acquisition was started after the sliding table had been moved into the center of the magnet. Coronal and sagittal T1-weighted images each required over 8 minutes to acquire, and T2-weighted images were obtained optionally. To assess the reliability of intraoperative evaluation of tumor resection, the intraoperative findings were compared with those on conventional postoperative 1.5-tesla MR images, which were obtained 2 to 3 months after surgery. Among 44 patients with large intra- and suprasellar pituitary adenomas that were mainly hormonally inactive, intraoperative MR imaging allowed an ultra-early evaluation of tumor resection in 73% of cases; such an evaluation is normally only possible 2 to 3 months after surgery. A second intraoperative examination of 24 patients for suspected tumor remnants led to additional resection in 15 patients (34%). CONCLUSIONS: Intraoperative MR imaging undoubtedly offers the option of a second look within the same surgical procedure, if incomplete tumor resection is suspected. Thus, the rate of procedures during which complete tumor removal is achieved can be improved. Furthermore, additional treatments for those patients in whom tumor removal was incomplete can be planned at an early stage, namely just after surgery.