With the development of neurosurgical techniques and corresponding instruments, the surgical treatment of pituitary adenomas is constantly being improved. Although the use of microsurgical transnasal butterfly treatment for pituitary adenomas is well established, the application of neuroendoscopic techniques in transnasal butterfly surgery has further improved the quality of surgical treatment for pituitary adenomas. From May 2000 to May 2006, we treated 678 pituitary adenomas with neuroendoscopic transnasal butterfly surgery, which are reported below.
1. Subjects and methods 1.1 General data 298 men and 380 women; age 14-80 years, average 36.5 years. There were 412 cases of headache, 346 cases of abnormal amenorrhea, 376 cases of lactation, 194 cases of acromegaly, 321 cases of visual acuity and visual field changes, 4 cases of ophthalmic nerve palsy, 20 cases of elevated blood glucose, 18 cases of elevated blood pressure, and 23 cases without any symptoms.
1.2 The tumors were located in the saddle area (mainly in the saddle) with a diameter of 0.5-4.5 cm, including 188 cases with a diameter of <1 cm, 441 cases with a diameter of 1-3 cm, and 49 cases with a diameter of >3 cm. There were 35 cases with growth in the paramedian, pterygoid sinus or slope.
1.3 Blood endocrine examination was performed in 371 cases with increased blood prolactin (PRL), 196 cases with increased blood growth hormone (GH), 16 cases with increased blood adrenocorticotropic hormone (ACTH), 1 case with increased blood thyroid hormone (TSH), and 5 cases with increased PRL+GH. The endocrine hormone was normal in 89 cases.
1.4 Surgical methods 1.4.1 Instruments: Rudolf Medical Instruments neuroendoscope, 4 mm diameter rigid mirror; automatic flushing pump; Sony monitor and video acquisition system.
1.4.2 Operation: General anesthesia with routine endotracheal intubation, patient in supine position, head tilted back 15°, 20° deflection towards the operator. The face and nasal cavity were disinfected with iodophor. The nostrils are selected based on preoperative CT and MRI findings of the head. A 30° endoscopic-guided approach was made along the middle turbinate and nasal septum, and the surgical access was dilated with a 0.01% norepinephrine saline tampon. The opening of the pterygoid sinus is revealed in the crypt of the pterygoid sinus. The bony structures of the anterior inferior wall of the pterygoid sinus are exposed, and the opening of the pterygoid sinus is widened by grinding the bone with a grinding drill, with a diameter of 1.5-2 cm; the septum of the pterygoid sinus is removed, and the internal carotid artery bulge on both sides of the pterygoid sinus is usually exposed, and the saddle base is completely exposed. The saddle base is grinded with an abrasive drill starting from the middle of the saddle base, and the opening area is 1~1.5 cm in diameter; the saddle base is punctured with a puncture needle, and after aspiration and exploration, the dura is electrocautery and cross-cut with a sharp knife, and the dura is cauterized and contracted to expose the tumor. When the tumor is large enough, the tumor can be resected with endoscopic exploration into the tumor cavity and the residual tumor can be removed under direct endoscopic view. After removal of the tumor, the tumor cavity can be filled with gelatin sponge or hemostatic gauze (surgical), and the saddle base can be closed with artificial dura double layer. If the mucosa of the nasal cavity on the operated side is well protected, there is no need to fill any substance.
2, Results 2.1 Surgical results 543 cases (80.1%) of total resection, 118 cases (17.4%) of subtotal resection, and 17 cases (2.5%) of partial resection. The postoperative clinical symptoms were improved to different degrees in 643 cases; 408 patients (99%) had significant relief of headache; 224 patients (69.8%) had recovery of visual acuity and visual field. 4 cases of preoperative actinic nerve palsy recovered. 2 patients who had rhinoplasty before surgery remained well after surgery. 15 patients with elevated blood glucose were relieved after surgery; 8 patients with preoperative hypertension improved after surgery. The preoperative blood PRL was normalized in 189 patients (50.9%), decreased by 80% in 104 patients (28%), and decreased by less than 80% in 78 patients (21%). Elevated GH decreased to normal after surgery in 133 patients (67.9%), with significant remission in 25 patients (12.8%) and no improvement in 38 patients (19.4%). The 5 patients with elevated blood PRL and GH all returned to normal after surgery. Of the 16 patients with increased ACTH, 14 (87.5%) recovered to normal, and 2 had no change in ACTH level in the early postoperative period. Among the 89 non-functioning adenomas, 18 patients were found to have hypothyroidism after surgery and required thyroxine supplementation, while the rest were unchanged.
2.2 Complications ①Two cases of subarachnoid hemorrhage were treated for two to three weeks, and they could take care of themselves at the time of discharge. Two cases of postoperative nasal hemorrhage were removed 3 days after the operation because the submucosal vessels were adhered to the oil gauze and pulled off, resulting in nasal hemorrhage, which was stopped by re-stuffing. Two cases of submucosal infection in the nose were treated satisfactorily by incision and drainage and local antibiotics. One case of postoperative external nostril narrowing was treated by local orthopedic surgery due to skin contracture caused by accidental electrocautery of the nasal vestibule tissue during surgery. The nasal leakage of cerebrospinal fluid in 14 cases after surgery, 8 of them were relieved by bed rest and drainage of cerebrospinal fluid from the lumbar pool for more than 2 weeks.
2.3 Follow-up: 420 cases (61.9%) were followed up from 6 to 24 months, including 199 cases of PRL adenoma, 180 cases of GH adenoma and 41 cases of non-functional adenoma. The blood PRL was normal in 121 patients (60.8%), while the remaining patients still needed oral bromocriptine treatment; blood GH was normal in 115 patients (63.9%), with significant remission in 27 patients (15%) and insignificant change in 38 patients (21%). 4 of the 420 patients had recurrence within 2 years after surgery.
The surgical treatment of pituitary tumors and related saddle lesions has improved significantly from the early days when only craniotomy was possible to remove the lesions to the last fifty years when transsphenoidal surgery was possible. However, social progress and scientific development have led people to pursue a higher quality of life. Surgeons are striving to minimize surgical trauma, remove the lesion as much as possible, reduce recurrence rate, lower disability rate and improve the quality of survival. The development and gradual improvement of neuroendoscopic technology is the result of the development of science and technology. Currently, neuroendoscopy is playing an increasingly widespread role in neurosurgery, and the technique of endoscopic transsphenoidal surgery to remove pituitary tumors is relatively mature. The core of this technique is to further reduce the trauma of the previous surgical approach, expand the exposure of the lesion, and increase the chance of visualizing the lesion.
Minimizing surgical trauma is a prerequisite for improving the quality of surgery. Cappabianca et al. emphasized that the absence of retractors and the use of the endoscope as an illumination and observation device are important features of endoscopic transnasal butterfly surgery. In this group, the natural space of the nasal cavity was used to gradually contract the nasal mucosa and expand the surgical access, thus avoiding septal fractures caused by forceful expansion with retractors. In expanding the opening of the pterygoid sinus, the anterior inferior wall of the pterygoid sinus, the septum of the pterygoid sinus and the base of the saddle were completely removed by grinding and drilling, which reduced the chance of intraoperative bleeding. Two patients in this group had undergone cosmetic rhinoplasty before the operation and did not have any adverse effects after this operation. We believe that by not using retractors in the dilated surgical access, we can increase the extent of lesion exposure and avoid unnecessary trauma. Intraoperative use of grinding drills for bony structures is an important part of reducing trauma and ensuring surgical safety.
Adequate exposure of the lesion is the guarantee of safe and effective resection of the tumor. Due to the optical illumination characteristics of the endoscope and the endoscopic angle and fisheye effect, it is easy to reveal the lesion at a close distance and increase the revealing range. The anatomical study of the endoscopic transnasal butterfly showed that the endoscopic exposure of the saddle area could clearly identify the bilateral optic chiasm elevation, bilateral internal carotid elevation, saddle base and slope depression, and some important anatomical landmarks of the cavernous sinus could be distinguished. In this group of cases, the scope of exposure is mainly based on the size, extent and growth direction of the lesion, but the basic scope of exposure should include the entire saddle base and slope depression. If the tumor growth is extensive or irregular, the exposure area should be selected individually according to the tumor growth direction and tumor characteristics. The structures of the pterygoid sinus and saddle area can usually be clearly identified by endoscopic observation of important anatomical landmarks, such as the internal carotid artery bulge. Therefore, intraoperative X-ray fluoroscopy is not necessary in most cases. In our group, intraoperative X-ray localization was performed only in 9 patients with complex structures in the pterygoid sinus and 2 patients with poor pneumatization of the pterygoid sinus.
The endoscope should be used as much as possible to remove the tumor under direct vision. In pituitary microadenomas, the tumor and normal tissue should be clearly identified under endoscopy to minimize the trauma to normal tissue. For larger pituitary adenomas, the advantages of endoscopy can be demonstrated. Usually, after partial removal of the tumor, the endoscope can be inserted into the tumor cavity to remove the residual tumor under direct vision and to observe the structure of the cavity. Moreland et al. and DeDivitiis et al. showed that the tumor can be completely removed by incising the anterior wall of the pterygoid sinus on one side only. In our clinical practice, we found that the choice of incising one side of the anterior wall of the anterior pterygoid sinus or a larger area depends on the growth characteristics of the tumor.
Jho et al [7] showed that endoscopic-assisted transsphenoidal surgery only improved the intraoperative visualization of transsphenoidal microsurgery, whereas endoscopic transsphenoidal surgery alone resulted in significantly less surgical trauma, minimal postoperative discomfort, and a significantly shorter hospital stay. In our group, the shortest postoperative hospital stay was 2 d. Because the endoscopic image was closer to the saddle area and the field of view was wider, more tumors could be removed under direct vision, which ensured safe and complete surgery and improved the quality of surgery. The cure rates of endoscopic surgery for pituitary tumors were 86% for ACTH adenomas, 89% for PRL adenomas, 87% for GH adenomas, and 93% for nonfunctional adenomas, with an overall recovery rate of 90%. The results of our group were similar to this report. We believe that endoscopic transnasal butterfly surgery for pituitary tumors increases the chances of total resection, with minimal postoperative reactions, and improves the cure rate.
An important advantage of endoscopic transsphenoidal surgery for pituitary tumors is its minimal invasiveness. cappabianca et al [15] used an endoscopic transsphenoidal approach to treat 146 pituitary tumors between 1997 and July 2001, with significantly fewer complications compared to the previous group of cases treated with bulk transsphenoidal microsurgery. In this group, various postoperative complications (including subarachnoid hemorrhage, postoperative nasal hemorrhage, nasal infection, nasal deformation, and cerebrospinal fluid nasal leak) occurred in 21 cases (3%). Of the 14 patients with cerebrospinal fluid nasal leakage, 4 underwent reoperation; 1 (0.15%) died 1 month after surgery due to a severe infection caused by cerebrospinal fluid leakage. The overall complications were significantly lower than those seen with conventional surgery.
In conclusion, endoscopic transsphenoidal surgery for pituitary tumors is a minimally invasive neurosurgical technique with minimal trauma, simple operation, and good therapeutic results, and will continue to develop and improve with the progress of science and technology.