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Section 4. Pituitary
Biomed Pharmacother 56 (2002) 171s–177s www.elsevier.com/locate/biopha
Mini review
Section 4. Pituitary New devices for direct transnasal surgery on pituitary adenomas Takumi Abe * Department of Neurosurgery, Showa University School of Medicine, 5-8 Hatanodai 1, Shinagawa-ku, Tokyo 142-8666, Japan
Abstract A micro-pressure-suction–irrigation system (MPSIS) is a surgical device that cleans the operative field of blood and tumor tissues with one-hand manipulation, dissects tumor tissue with its rapid flow, and removes debris by suction without injury to the normal tissue structures. Since 1997, good transnasal surgical results for pituitary adenomas have been achieved in Japan using this system. However, the surgical results for large, fibrous pituitary adenomas were unfavorable. Ultrasonic surgical aspirators with needle-type probes and an electromagnetic field system, all recently developed in Japan, are improving the results of direct transnasal surgery on pituitary adenomas. The MPSIS effectively dissects typical adenoma tissue with rapid irrigation and removes it by suction. A tumor in the cavernous sinus was removed by this system under direct vision in combination with pituitary mirrors. Fibrous adenomas were resected using ultrasonic surgical aspirators with needle-type probes. Thick mucosa and a firm tumor were vaporized with an electromagnetic field system. The sellar floor was reconstructed with combined ceramics, used in cases requiring additional surgery or drainage of cerebrospinal fluid leakage during surgery. Direct transnasal surgery with these devices was performed to remove 143 pituitary adenomas. Most of these pituitary adenomas could be selectively removed except for those lesions with extensive cavernous sinus invasion. There was no surgical morbidity or mortality. With the advancement of surgical technique and the development of surgical devices, most pituitary adenomas, even those that are fibrous or firm, can be removed via the transnasal route. © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved. Keywords: Micro-pressure-suction–irrigation system; Needle-type ultrasonic surgical aspirator; Eelectromagnetic field system
1. Introduction Transsphenoidal surgery is widely performed on patients with pituitary adenomas because of its relative simplicity and satisfactory results. The first direct transnasal surgery for pituitary adenomas was reported by Hirsch in the early 1900s [21]. The technique has been further developed by Landolt et al. and Lüdecke in the 1970s [25,26]. A micropressure-suction–irrigation system (MPSIS) was designed for the direct transnasal surgical removal of pituitary adenomas by Lüdecke and Treige [27]. The results of direct transnasal surgery for pituitary tumors have improved with the use of this system [1,3-8,11,16,22,24,28,30]. In Japan, the first direct transnasal pituitary surgery was reported in the early 1990s [17,23]. In general, the sublabial transsphe* Corresponding author. Tel.: +81-3-3784-8605; fax: +81-3-3784-8432. E-mail address: [email protected] (T. Abe). © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved. PII: S 0 7 5 3 - 3 3 2 2 ( 0 2 ) 0 0 2 1 0 - X
noidal approach is performed for removing pituitary adenomas because Japanese nostrils are believed to be too small and narrow for the transnasal approach. The MPSIS has been improved for use in Japan, and direct transnasal surgery has been performed on patients with pituitary adenomas since 1997 with good surgical results [9]. The surgical results of fibrous and large pituitary adenomas have been reported to be unfavorable [19,31]. Staged transsphenoidal surgery for fibrous pituitary adenomas with suprasellar extension has been attempted but total removal of the tumors was difficult [2]. The MPSIS was also less useful for the removal of fibrous adenomas, especially in a second transnasal operation. Thus, some additional surgeries were performed with a transcranial approach. The ultrasonic surgical aspirator is the most commonly used instrument to remove firm tumors that would prove difficult to remove with cautery and suction [18]. However, because the large sizes of currently available handpieces have rendered them
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inadequate for excision of deeply situated tumors and for work in critical areas, the ultrasonic surgical aspirator has not been used for the transsphenoidal pituitary surgery. To address several disadvantages of currently available ultrasonic aspirators used in microsurgery, ultrasonic surgical aspirators with needle-type probes were recently developed in Japan [32]. With this device, fibrous adenomas have been removed via the transnasal route [12]. Electroconvergent cautery, introduced by Patil and Yamanashi in 1994 [29], has undergone several generations of development in Japan [20]. The electromagnetic field system is a high frequency surgical device that can vaporize, cut, and coagulate tissue without damage to surrounding structures in cases of skull base and deep-seated tumor resection. This system is now being tested for use in transnasal pituitary surgery [15]. This report describes the use of these new devices for improving the results of direct transnasal surgery on pituitary adenomas.
A
2. Descriptions of new devices 2.1. Micro-pressure-suction–irrigation system The MPSIS was constructed at the laboratory of Waldemar Link, GMBH&Co. (Hamburg, Germany). An overall view of the principal parts of MPSIS is shown in Fig. 1. This system consists of a handpiece with a suction–irrigation tube and a fluid pressure-generating system. The fluid pressure is provided by a special pressure tank, which is connected to the air pressure source. The pressures of suction and irrigation are adjusted by a thumb control in the handpiece (Fig. 1A). The suction–irrigation tip consists of two tubes: the larger, outer tube is for suction while the smaller, inner cannula provides irrigation. Separate tips of various lengths and angles are adjustable for different surgical stages (Fig. 1B). The MPSIS effectively cleans the operative field of blood and tumor tissues with one-hand manipulation, dissects tumor tissue with rapid irrigation, and removes debris with suction. The use of the MPSIS minimizes injury to normal tissue structures. Micro-mirrors with four different sizes are available. The angle of the micro-mirror is adjustable in every direction from its handle attachment. This system is especially useful in combination with micro-mirrors for direct inspection of eccentric tumor sites, such as the cavernous sinus and suprasellar regions (Fig. 2A). These tumor sites may be obliterated by using a suction–irrigation device with a curved tip under direct vision, avoiding injury to the normal pituitary gland (Fig. 2B). The MPSIS is also an effective device in endoscopic transnasal surgery on pituitary adenomas. The MPSIS clears the endoscopic visual field by irrigating the tip of the endoscope, eliminating the need to take the endoscopic
B Fig. 1. (A) Suction–irrigation device and handpiece for regulation of suction and irrigation. The suction–irrigation device, 130 mm in length, consists of a larger tube for suction and a small indwelling cannula for irrigation that ends 2 mm before the tip of the outer tube. (B) Different angles and lengths of the tip of the suction–irrigation device: angled up 90° and short, medium, and long; straight and 2.0, 3.0, and 3.5 mm in diameter; angled down 90° and short, medium, and long.
device outside the operative field to clean it. Extrasellar tumors were resected using the MPSIS with angled tips under endoscopic guidance with wide visualization [10]. Bipolar coagulation forceps with curved tips are available for working in the corners of the operating site under view. 2.2. Ultrasonic surgical aspirators with needle-type probes (OUSAt and SONOPETt) The major disadvantages of currently available ultrasonic surgical aspirators in neurosurgery include the following: (1) the heavy weight of the handpiece; (2) the large size of the handpiece, which can obstruct the surgeon’s view of the field through an operating microscope; (3) the thickness of the probe tip, which renders it unsuitable for microsurgical manipulation; and (4) the inappropriate shape of the probe, which renders it incapable of reaching deep-seated lesions. A new handpiece, probe, and probe sheaths were designed
T. Abe / Biomed Pharmacother 56 (2002) 171s–177s
A
B Fig. 2. Micro-mirror technique (A) and operative schema (B) demonstrating the removal of the eccentric tumor part under direct vision using an MPSIS with the device tip angled up 90° (a) and in combination with a pituitary micro-mirror (b).
to overcome these disadvantages. The ultrasonic aspiration system is composed of a power supply unit, a suction unit, a handpiece, probes with sheaths, and a foot switch. The suction function can be either synchronized with vibration or used alone. The surgical field is continuously irrigated with normal saline solution, which emerges near the probe tip, through the sheath. Two types of needle-type ultrasonic surgical aspirators are used in Japan: one was constructed at the laboratory of Olympus Optical Co. (OUSAt, Tokyo,
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Japan) and the other at the laboratory of M&M Co. (SONOPETt, Tokyo, Japan). The differences in design between the two ultrasonic surgical aspirators are described in Table 1. The power supply unit, handpieces, and probes reported here are now commercially available in Japan. The OUSAt ultrasonic aspiration system (Fig. 3A) was designed by Sawamura et al. [32]. The weight of the handpiece has been reduced to 90 g. The needle-type probe has a 171-mm length, a 1.9-mm tip diameter, and a 3.3-mm sheath diameter, and produces a tip amplitude of 70 µm at the ultrasonic frequency of 23.5 kHz. This probe bends at an angle of 25° to the handpiece. The handpiece has a high-power irrigation function (300 ml/min) that is controlled with a foot switch. This device was first used for the transnasal removal of fibrous adenomas that could not be extirpated by the suction–irrigation system or ordinary instruments [12]. However, although the handpiece became smaller and lighter, a tip amplitude of 70 µm may be insufficient ultrasonic power for the fragmentation of firm tumors. In the SONOPETt ultrasonic aspiration system (Fig. 3B), the handpiece weight is 100 g. The needle-type probe has a 139-mm length and a 1.9-mm tip diameter, and produces a tip amplitude of 300 µm at the ultrasonic frequency of 25 kHz. A tip amplitude of 300 µm appears to be sufficient power for the fragmentation of firm tumors. The usefulness of the SONOPETt system for the removal of firm adenomas via the transnasal route has previously been reported [15]. However, because the outer diameter of the proximal end of sheath is 8 mm, the handpiece sometimes obstructed the surgeon’s view of the field through an operating microscope. 2.3. Electromagnetic field system (PAL-It) The electromagnetic field system (PAL-It) was constructed at the laboratory of Japan Medical Dynamic Marketing, Inc., Japan. The PAL-It system contains a neurosurgical device that generates a high frequency wave signal of 13.56 MHz to vaporize, cut, and coagulate tissue. This energy is extremely precise and is focused at the tip of the handpiece electrode. This pinpoint energy does not cause
Table 1 Design of handpiece and needle-type probe in two types of ultrasonic surgical aspirators
Handpiece weight (g) Valid probe length (mm) Inner diameter of distal end tip (mm) Probe angle (°) Outer diameter of proximal end of sheath (mm) Maximum tip amplitude (µm) Aspiration pressure (mmHg) Irrigation flow rate (ml/min)
OUSAt
SONOPETt
90 171 1.9 25 3.3 70 0–670 15–140
100 139 1.9 25 8 300 0–500 3–40
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A
Fig. 4. Electromagnetic field system (PAL-It). This neurosurgical device for transnasal pituitary surgery has a 140-mm tip length and a 1.2-mm tip diameter. It generates a high frequency wave signal of 13.56 MHz to vaporize, cut, and coagulate firm tissue.
vaporized during transnasal surgery [15]. Thus, the PAL-It system has proven to reduce surgical time.
3. Clinical application
B Fig. 3. Ultrasonic needle-type surgical aspirators. (A) Olympus ultrasonic surgical aspirator (OUSAt). The handpiece weighs 90 g. The needle-type probe has a 171-mm length, a 1.9-mm tip diameter, and a 3.3-mm sheath diameter and produces a tip amplitude of 70 µm. This probe bends at an angle of 25° to the handpiece. (B) Ultrasmall long angled handpiece (SONOPETt). The handpiece weighs 100 g. The needle-type probe has a 139-mm length, a 1.9-mm tip diameter, and produces a tip amplitude of 300 µm.
damage or thermal necrosis to surrounding structures, cranial nerves, perforating arteries, and other vital structures when the device is used with a grounding pad. The neurosurgical bayonet and pencil-type handpieces of the PAL-It system are small and flexible so they do not obstruct the surgeon’s field of view under a microscope. Not only is the handpiece small and easy to use, it is also very light and the cable is flexible, allowing the surgeon full control without restricting movement. The PAL-It system has been used for the vaporization and coagulation of skull base and deep-seated firm tumors, especially meningiomas [20]. A longer tip is now being designed for transnasal pituitary surgery. This tip with a 140-mm length and a 1.2-mm tip diameter is not now commercially available; it has been used clinically only by our group (Fig. 4). With this system, fibrous connective tissue and firm tumor tissue is easily
Since 1997, direct transnasal surgery has been performed to remove 143 pituitary adenomas (56 nonfunctioning adenomas, 42 prolactin-secreting adenomas, 32 growth hormone (GH)-secreting adenomas, 12 adrenocorticotropic hormone (ACTH)-secreting adenomas, and one thyrotropinsecreting adenoma) using the MPSIS, OUSAt, SONOPETt, and PAL-It systems. Bone window CT slices parallel to the transnasal surgical route provided direct visualization of the nasal anatomy for the approach. This method was helpful for determining the lateral extent of the sella floor requiring removal, especially in cases with previous surgeries [13]. Using MPSIS, typical soft adenomas could be dissected by rapid irrigation and removed by suction without injury to the normal pituitary gland. Slight tumor invasion in the cavernous sinus was obliterated by this system under direct vision in combination with micro-mirrors. Thus, pituitary adenomas could be selectively removed in all patients except those with extensive cavernous sinus invasion, with MPSIS. Fibrous adenomas, such as prolactin-secreting adenomas during dopamine agonist therapy or nonfunctioning adenomas found in subsequent surgery, were resected using the OUSAt or the SONOPETt systems. The PAL-It system was originally used to vaporize the thick mucosa and fibrous tissues in the nasal cavity and sphenoid sinus. Recently, it was used to vaporize the firm tumor tissue in the sella floor under direct vision. Firm adenomas could be reduced with the OUSAt, SONOPETt, and PAL-It systems. The pressures of aspiration, irrigation, and power of these devices were set accord-
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ing to the nature of the tumor. If the character of the tissues was in doubt, a biopsy of the tissue was performed and the tumor tissue was selectively resected. The sella floor was reconstructed with ceramics composed of a combination of hydroxyapatite and tricalcium phosphate, to facilitate additional surgery and drainage of cerebrospinal fluid leakage during surgery [14]. There was no surgical morbidity or mortality. 3.1. Representative cases 3.1.1. Patient 1: tumor removal with MPSIS A 30-year-old male presented with a sudden-onset headache and visual disturbance. He showed no typical physical symptoms of Cushing’s disease. Neurological examination showed blindness in the left eye and a defect of the lateral visual field in the right eye. A few hours later, he showed a left-sided cavernous sinus syndrome (exophthalmos, chemosis, and oculomotor nerve palsy). On endocrinological examination, serum ACTH and cortisol levels were markedly elevated. The basal levels of other hormones were within normal range. A magnetic resonance (MR) imaging revealed an intra- and suprasellar mass with a pituitary hemorrhage and extension of the hemorrhage to the anterior skull base (Fig. 5A). The tumor was successfully removed via the transnasal route by using MPSIS in combination with micro-mirrors. After surgery, the patient’s left-sided cavernous sinus syndrome and right-sided temporal hemianopsia were immediately resolved. Serum ACTH and cortisol levels declined to within normal range. Subsequent MR images revealed no tumor recurrence 3 years after surgery (Fig. 5B). 3.1.2. Patient 2: tumor resection with MPSIS and the SONOPETt system A 33-year-old female presented with bitemporal hemianopsia and acromegalic features. Preoperative serum GH and IGF-I levels were elevated. This patient had undergone transnasal exploration for a GH-secreting pituitary adenoma with left-sided cavernous sinus invasion. After surgery, serum GH and IGF-I levels were still elevated. An MR imaging demonstrated a residual adenoma in the left cavernous sinus. Treatments with dopamine agonist and octreotide were not effective. Gamma knife stereotactic radiosurgery was performed on the residual tumor 6 months after surgery. However, 4 months after radiosurgery, serum GH and IGF-I levels were still elevated. Another MR imaging showed regrowth of the residual tumor (Fig. 6A). This patient underwent a second transnasal pituitary exploration. This tumor, especially fibrous, was partially resected by using MPSIS and the SONOPETt system. After surgery, serum GH and IGF-I levels were slightly elevated. An additional MR imaging revealed a partial resection of the
A
B Fig. 5. Sagittal enhanced T1-weighted MR images at admission (A) and 3 years after surgery (B). (A) MR image showing an intra- and suprasellar mass with an acute pituitary hemorrhage and a hematoma extending to the anterior base of the skull. (B) MR image revealing no tumor recurrence.
residual tumor (Fig. 6B). This patient is receiving follow-up care without medical treatment. 3.1.3. Patient 3: tumor vaporization with the PAL-It system A 35-year-old male presented with hyperthyroidism and visual field defect. Physical examination noted acromegalic features. Endocrinological and radiological examinations revealed a thyrotropin-, GH-, and prolactin-secreting pituitary adenoma. After octreotide treatment for 1 month (300 µm/d), this patient underwent partial tumor removal via the sublabial transsphenoidal route at another hospital. After surgery, an MR imaging demonstrated a large intraand suprasellar residual tumor with right cavernous sinus invasion (Fig. 7A). Endocrinological examination revealed elevated serum thyrotropin, free-T3, free-T4, GH, IGF-I, and prolactin levels. A second transnasal pituitary surgery was performed. The thick mucosa and fibrous tissues in the nasal cavity and sphenoid sinus were vaporized using the PAL-It system. The tumor was especially fibrous and firm,
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A
A
B
B
Fig. 6. Coronal enhanced T1-weighted MR images 4 months after radiosurgery (A) and 2 weeks after secondary surgery (B). (A) MR image revealing regrowth of the residual tumor after radiosurgery. (B) MR image demonstrating partial resection of the residual fibrous tumor using MPSIS and SONOPETt.
Fig. 7. Sagittal enhanced T1-weighted MR images 1 year after the first transsphenoidal surgery (A) and 1 month after secondary transnasal surgery (B). (A) MR image showing a large, firm intra- and suprasellar residual tumor with the right-sided cavernous sinus invasion. (B) MR image revealing partial resection of the residual firm tumor using PAL-It.
and thus could not be resected by usual surgical instruments, MPSIS, or the SONOPETt system. The firm intrasellar lesion was vaporized using the PAL-It system after confirmation of tumor tissue type by a biopsy. Another MR imaging revealed a partial resection of the firm tumor after surgery (Fig. 7B).
References
4. Conclusions The suitability and usefulness of the MPSIS, ultrasonic surgical aspirators with needle-type probes, and the electromagnetic field system for direct transnasal pituitary exploration have been proven. With the advancement of surgical technique and development of surgical instruments, most pituitary adenomas can now be removed via the transnasal route.
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Abe T, Lüdecke DK. Recent results of primary transnasal surgery for infradiaphragmatic craniopharyngiomas. Neurosurg Focus 1997;3: 1–6. Abe T, Iwata T, Kawamura N, Izumiyama H, Ikeda H, Matsumoto K. Staged transsphenoidal surgery for fibrous nonfunctioning pituitary adenomas with suprasellar extension. Neurol Med Chir (Tokyo) 1997;37:830–7. Abe T, Lüdecke DK, Saeger W. Clinically nonsecreting pituitary adenomas in childhood and adolescence. Neurosurgery 1998;42: 744–51. Abe T, Lüdecke DK. Recent results of secondary transnasal surgery for residual or recurring acromegaly. Neurosurgery 1998;42: 1013–22. Abe T, Lüdecke DK. Recent primary transnasal surgical outcomes associated with intraoperative growth hormone measurement in acromegaly. Clin Endocrinol (Oxf) 1999;50:27–35. Abe T, Lüdecke DK. Transnasal surgery for infradiaphragmatic craniopharyngiomas in children. Neurosurgery 1999;44:957–66.
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Abe T, Abou Tara L, Lüdecke DK. Growth hormone-secreting pituitary adenomas in childhood and adolescence: features and results of transnasal surgery. Neurosurgery 1999;45:1–10. Abe T, Lüdecke DK. Mucocele-like formation leading to neurological symptoms in prolactin-secreting pituitary adenomas under dopamine agonist therapy. Surg Neurol 1999;52:274–9. Abe T, Matsumoto K, Shimazu M, Jimbo H, Sunaga S, Dohi K, Sasaki K, Izumiyama H, Ohki S, Fujitani S. Transnasal microsurgery using a micro-pressure-suction–irrigation system for pituitary adenomas. No Shinkei Geka 1999;27:225–31 Japanese, English abstract. Abe T, Matsumoto K, Ohki S, Suzaki H. Endoscope-assisted transnasal resection for pituitary adenomas. Showa Univ J Med Sci 1999;59:87–91 Japanese, English abstract. Abe T, Lüdecke DK. Effects of preoperative octreotide treatment on different subtypes of 90 growth hormone-secreting pituitary adenomas and outcome in one surgical center. Eur J Endocrinol 2001;145:137–45. Abe T, Imaizumi Y, Nakamura Y, Kawamura N, Hayashi M, Ikeda H, Izumiyama H, Matsumoto K, Fujitani S. Transnasal reoperations for fibrous pituitary adenomas: preliminary experiences using both micro-pressure-suction–irrigation system and needle type ultrasonic surgical aspiration. Jpn J Neurosurg (Tokyo) 2001;10: 320–5 Japanese, English abstract. Abe T, Kawamura N, Izumiyama H, Wada A, Hatayama K, Kobayashi N, Ikeda H, Matsumoto K. The usefulness of bone window CT images parallel to the transnasal surgical route for pituitary diseases. Prog Computed Imaging 2001;23:109–15 Japanese, English abstract. Abe T, Matsumoto K, Kushima M. Reconstruction of the sellar floor during transnasal pituitary surgery using ceramics composed of a combination of hydroxyapatite and tricalcium phosphate. No Shinkei Geka 2001;29:511–5 Japanese, English abstract. Abe T, Kawamura N, Kunii N, Shimazu M, Jimbo H, Ikeda H, Izumiyama H, Matsumoto K. Direct transnasal surgery for pituitary adenomas using micro-pressure-suction–irrigation system and ultrasonic surgical aspirator with needle-type probe. 12th World Congress of Neurosurgery. 2001. p. 176 abstract. Abe T, Lüdecke DK. Transnasal surgery for prolactin-secreting pituitary adenomas in childhood and adolescence. Surg Neurol (in press). Arita K, Uozumi T, Yano T, Kurisu K, Hirohata T, Sadamoto T, Takechi A, Eguchi K, Iida K. Oral complication of sublabial transsphenoidal surgery and advantages of endonasal transsphenoidal approach. No Shinkei Geka 1994;22:119–24 Japanese, English abstract.
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[18] Flamm ES, Ransohoff J, Wuchinich D, Broadwin A. Preliminary experience with ultrasonic aspiration in neurosurgery. Neurosurgery 1978;2:240–5. [19] Hashimoto N, Handa H, Yamashita J, Yamagami T. Long-term follow-up of large or invasive pituitary adenomas. Surg Neurol 1986;25:49–54. [20] Hashimoto T, Patil AA, Yamanashi W, Shimazu H, Zhao W. Usefulness of electromagnetic field (EMF) system in skull base and deep seated brain tumors. Proceedings of the 11th European Congress of Neurosurgery. Bologna, Italy: Monduzzi; 1999. p. 401–6. [21] Hirsch O. Endonasal method of removal of hypophyseal tumours with report of two successful cases. JAMA 1910;55:772–4. [22] Knappe UJ, Lüdecke DK. Transnasal microsurgery in children and adolescents with Cushing’s disease. Neurosurgery 1996;39:484–93. [23] Kurisaka M, Sada Y, Honda S, Mori K. Endonasal unilateral-septal transsphenoidal approach for pituitary tumors. . Surgery (Jpn) 1990;44:1781–6 Japanese. [24] König A, Lüdecke DK, Herrmann HD. Transnasal surgery in the treatment of craniopharyngiomas. Acta Neurochir (Wien) 1986;83: 1–7. [25] Landolt AM, Strebel P. Technique of transsphenoidal operation for pituitary adenomas. In: Krayenbuhl H, editor. Advances and technical standards in neurosurgery, vol 7. Wien: Springer; 1980. p. 119–71. [26] Lüdecke DK. Lüdecke instrumentation for the direct transnasal pituitary procedure. Hamburg: Waldemar Link; 1986. p. 1–33. [27] Lüdecke DK, Treige W. Pressure-irrigation–suction system. Technical note. Acta Neurochir (Wien) 1982;66:123–6. [28] Lüdecke DK, Knappe UJ, Glagla G. Cushing’s disease: surgical results and prognosis. In: Landolt AM, Vance ML, Reilly PL, editors. Pituitary adenomas. New York: Churchill Livingstone; 1996. p. 353–61. [29] Patil AA, Yamanashi W. Electroconvergent cautery. Neurosurgery 1994;35:785–8. [30] Puchner MJA, Knappe UJ, Lüdecke DK. Pituitary surgery in elderly patients with acromegaly. Neurosurgery 1995;36:677–84. [31] Saito K, Kuwayama A, Yamamoto N, Sugita K. The transsphenoidal removal of nonfunctioning pituitary adenomas with suprasellar extension: the open sella method and intentionally staged operation. Neurosurgery 1995;36:668–76. [32] Sawamura Y, Fukushima T, Terasaka S, Sugai T. Development of a handpiece and probes for a microsurgical ultrasonic aspirators: instrumentation and application. Neurosurgery 1999;45:1192–7.
Mini review
Section 4. Pituitary New devices for direct transnasal surgery on pituitary adenomas Takumi Abe * Department of Neurosurgery, Showa University School of Medicine, 5-8 Hatanodai 1, Shinagawa-ku, Tokyo 142-8666, Japan
Abstract A micro-pressure-suction–irrigation system (MPSIS) is a surgical device that cleans the operative field of blood and tumor tissues with one-hand manipulation, dissects tumor tissue with its rapid flow, and removes debris by suction without injury to the normal tissue structures. Since 1997, good transnasal surgical results for pituitary adenomas have been achieved in Japan using this system. However, the surgical results for large, fibrous pituitary adenomas were unfavorable. Ultrasonic surgical aspirators with needle-type probes and an electromagnetic field system, all recently developed in Japan, are improving the results of direct transnasal surgery on pituitary adenomas. The MPSIS effectively dissects typical adenoma tissue with rapid irrigation and removes it by suction. A tumor in the cavernous sinus was removed by this system under direct vision in combination with pituitary mirrors. Fibrous adenomas were resected using ultrasonic surgical aspirators with needle-type probes. Thick mucosa and a firm tumor were vaporized with an electromagnetic field system. The sellar floor was reconstructed with combined ceramics, used in cases requiring additional surgery or drainage of cerebrospinal fluid leakage during surgery. Direct transnasal surgery with these devices was performed to remove 143 pituitary adenomas. Most of these pituitary adenomas could be selectively removed except for those lesions with extensive cavernous sinus invasion. There was no surgical morbidity or mortality. With the advancement of surgical technique and the development of surgical devices, most pituitary adenomas, even those that are fibrous or firm, can be removed via the transnasal route. © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved. Keywords: Micro-pressure-suction–irrigation system; Needle-type ultrasonic surgical aspirator; Eelectromagnetic field system
1. Introduction Transsphenoidal surgery is widely performed on patients with pituitary adenomas because of its relative simplicity and satisfactory results. The first direct transnasal surgery for pituitary adenomas was reported by Hirsch in the early 1900s [21]. The technique has been further developed by Landolt et al. and Lüdecke in the 1970s [25,26]. A micropressure-suction–irrigation system (MPSIS) was designed for the direct transnasal surgical removal of pituitary adenomas by Lüdecke and Treige [27]. The results of direct transnasal surgery for pituitary tumors have improved with the use of this system [1,3-8,11,16,22,24,28,30]. In Japan, the first direct transnasal pituitary surgery was reported in the early 1990s [17,23]. In general, the sublabial transsphe* Corresponding author. Tel.: +81-3-3784-8605; fax: +81-3-3784-8432. E-mail address: [email protected] (T. Abe). © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved. PII: S 0 7 5 3 - 3 3 2 2 ( 0 2 ) 0 0 2 1 0 - X
noidal approach is performed for removing pituitary adenomas because Japanese nostrils are believed to be too small and narrow for the transnasal approach. The MPSIS has been improved for use in Japan, and direct transnasal surgery has been performed on patients with pituitary adenomas since 1997 with good surgical results [9]. The surgical results of fibrous and large pituitary adenomas have been reported to be unfavorable [19,31]. Staged transsphenoidal surgery for fibrous pituitary adenomas with suprasellar extension has been attempted but total removal of the tumors was difficult [2]. The MPSIS was also less useful for the removal of fibrous adenomas, especially in a second transnasal operation. Thus, some additional surgeries were performed with a transcranial approach. The ultrasonic surgical aspirator is the most commonly used instrument to remove firm tumors that would prove difficult to remove with cautery and suction [18]. However, because the large sizes of currently available handpieces have rendered them
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T. Abe / Biomed Pharmacother 56 (2002) 171s–177s
inadequate for excision of deeply situated tumors and for work in critical areas, the ultrasonic surgical aspirator has not been used for the transsphenoidal pituitary surgery. To address several disadvantages of currently available ultrasonic aspirators used in microsurgery, ultrasonic surgical aspirators with needle-type probes were recently developed in Japan [32]. With this device, fibrous adenomas have been removed via the transnasal route [12]. Electroconvergent cautery, introduced by Patil and Yamanashi in 1994 [29], has undergone several generations of development in Japan [20]. The electromagnetic field system is a high frequency surgical device that can vaporize, cut, and coagulate tissue without damage to surrounding structures in cases of skull base and deep-seated tumor resection. This system is now being tested for use in transnasal pituitary surgery [15]. This report describes the use of these new devices for improving the results of direct transnasal surgery on pituitary adenomas.
A
2. Descriptions of new devices 2.1. Micro-pressure-suction–irrigation system The MPSIS was constructed at the laboratory of Waldemar Link, GMBH&Co. (Hamburg, Germany). An overall view of the principal parts of MPSIS is shown in Fig. 1. This system consists of a handpiece with a suction–irrigation tube and a fluid pressure-generating system. The fluid pressure is provided by a special pressure tank, which is connected to the air pressure source. The pressures of suction and irrigation are adjusted by a thumb control in the handpiece (Fig. 1A). The suction–irrigation tip consists of two tubes: the larger, outer tube is for suction while the smaller, inner cannula provides irrigation. Separate tips of various lengths and angles are adjustable for different surgical stages (Fig. 1B). The MPSIS effectively cleans the operative field of blood and tumor tissues with one-hand manipulation, dissects tumor tissue with rapid irrigation, and removes debris with suction. The use of the MPSIS minimizes injury to normal tissue structures. Micro-mirrors with four different sizes are available. The angle of the micro-mirror is adjustable in every direction from its handle attachment. This system is especially useful in combination with micro-mirrors for direct inspection of eccentric tumor sites, such as the cavernous sinus and suprasellar regions (Fig. 2A). These tumor sites may be obliterated by using a suction–irrigation device with a curved tip under direct vision, avoiding injury to the normal pituitary gland (Fig. 2B). The MPSIS is also an effective device in endoscopic transnasal surgery on pituitary adenomas. The MPSIS clears the endoscopic visual field by irrigating the tip of the endoscope, eliminating the need to take the endoscopic
B Fig. 1. (A) Suction–irrigation device and handpiece for regulation of suction and irrigation. The suction–irrigation device, 130 mm in length, consists of a larger tube for suction and a small indwelling cannula for irrigation that ends 2 mm before the tip of the outer tube. (B) Different angles and lengths of the tip of the suction–irrigation device: angled up 90° and short, medium, and long; straight and 2.0, 3.0, and 3.5 mm in diameter; angled down 90° and short, medium, and long.
device outside the operative field to clean it. Extrasellar tumors were resected using the MPSIS with angled tips under endoscopic guidance with wide visualization [10]. Bipolar coagulation forceps with curved tips are available for working in the corners of the operating site under view. 2.2. Ultrasonic surgical aspirators with needle-type probes (OUSAt and SONOPETt) The major disadvantages of currently available ultrasonic surgical aspirators in neurosurgery include the following: (1) the heavy weight of the handpiece; (2) the large size of the handpiece, which can obstruct the surgeon’s view of the field through an operating microscope; (3) the thickness of the probe tip, which renders it unsuitable for microsurgical manipulation; and (4) the inappropriate shape of the probe, which renders it incapable of reaching deep-seated lesions. A new handpiece, probe, and probe sheaths were designed
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B Fig. 2. Micro-mirror technique (A) and operative schema (B) demonstrating the removal of the eccentric tumor part under direct vision using an MPSIS with the device tip angled up 90° (a) and in combination with a pituitary micro-mirror (b).
to overcome these disadvantages. The ultrasonic aspiration system is composed of a power supply unit, a suction unit, a handpiece, probes with sheaths, and a foot switch. The suction function can be either synchronized with vibration or used alone. The surgical field is continuously irrigated with normal saline solution, which emerges near the probe tip, through the sheath. Two types of needle-type ultrasonic surgical aspirators are used in Japan: one was constructed at the laboratory of Olympus Optical Co. (OUSAt, Tokyo,
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Japan) and the other at the laboratory of M&M Co. (SONOPETt, Tokyo, Japan). The differences in design between the two ultrasonic surgical aspirators are described in Table 1. The power supply unit, handpieces, and probes reported here are now commercially available in Japan. The OUSAt ultrasonic aspiration system (Fig. 3A) was designed by Sawamura et al. [32]. The weight of the handpiece has been reduced to 90 g. The needle-type probe has a 171-mm length, a 1.9-mm tip diameter, and a 3.3-mm sheath diameter, and produces a tip amplitude of 70 µm at the ultrasonic frequency of 23.5 kHz. This probe bends at an angle of 25° to the handpiece. The handpiece has a high-power irrigation function (300 ml/min) that is controlled with a foot switch. This device was first used for the transnasal removal of fibrous adenomas that could not be extirpated by the suction–irrigation system or ordinary instruments [12]. However, although the handpiece became smaller and lighter, a tip amplitude of 70 µm may be insufficient ultrasonic power for the fragmentation of firm tumors. In the SONOPETt ultrasonic aspiration system (Fig. 3B), the handpiece weight is 100 g. The needle-type probe has a 139-mm length and a 1.9-mm tip diameter, and produces a tip amplitude of 300 µm at the ultrasonic frequency of 25 kHz. A tip amplitude of 300 µm appears to be sufficient power for the fragmentation of firm tumors. The usefulness of the SONOPETt system for the removal of firm adenomas via the transnasal route has previously been reported [15]. However, because the outer diameter of the proximal end of sheath is 8 mm, the handpiece sometimes obstructed the surgeon’s view of the field through an operating microscope. 2.3. Electromagnetic field system (PAL-It) The electromagnetic field system (PAL-It) was constructed at the laboratory of Japan Medical Dynamic Marketing, Inc., Japan. The PAL-It system contains a neurosurgical device that generates a high frequency wave signal of 13.56 MHz to vaporize, cut, and coagulate tissue. This energy is extremely precise and is focused at the tip of the handpiece electrode. This pinpoint energy does not cause
Table 1 Design of handpiece and needle-type probe in two types of ultrasonic surgical aspirators
Handpiece weight (g) Valid probe length (mm) Inner diameter of distal end tip (mm) Probe angle (°) Outer diameter of proximal end of sheath (mm) Maximum tip amplitude (µm) Aspiration pressure (mmHg) Irrigation flow rate (ml/min)
OUSAt
SONOPETt
90 171 1.9 25 3.3 70 0–670 15–140
100 139 1.9 25 8 300 0–500 3–40
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Fig. 4. Electromagnetic field system (PAL-It). This neurosurgical device for transnasal pituitary surgery has a 140-mm tip length and a 1.2-mm tip diameter. It generates a high frequency wave signal of 13.56 MHz to vaporize, cut, and coagulate firm tissue.
vaporized during transnasal surgery [15]. Thus, the PAL-It system has proven to reduce surgical time.
3. Clinical application
B Fig. 3. Ultrasonic needle-type surgical aspirators. (A) Olympus ultrasonic surgical aspirator (OUSAt). The handpiece weighs 90 g. The needle-type probe has a 171-mm length, a 1.9-mm tip diameter, and a 3.3-mm sheath diameter and produces a tip amplitude of 70 µm. This probe bends at an angle of 25° to the handpiece. (B) Ultrasmall long angled handpiece (SONOPETt). The handpiece weighs 100 g. The needle-type probe has a 139-mm length, a 1.9-mm tip diameter, and produces a tip amplitude of 300 µm.
damage or thermal necrosis to surrounding structures, cranial nerves, perforating arteries, and other vital structures when the device is used with a grounding pad. The neurosurgical bayonet and pencil-type handpieces of the PAL-It system are small and flexible so they do not obstruct the surgeon’s field of view under a microscope. Not only is the handpiece small and easy to use, it is also very light and the cable is flexible, allowing the surgeon full control without restricting movement. The PAL-It system has been used for the vaporization and coagulation of skull base and deep-seated firm tumors, especially meningiomas [20]. A longer tip is now being designed for transnasal pituitary surgery. This tip with a 140-mm length and a 1.2-mm tip diameter is not now commercially available; it has been used clinically only by our group (Fig. 4). With this system, fibrous connective tissue and firm tumor tissue is easily
Since 1997, direct transnasal surgery has been performed to remove 143 pituitary adenomas (56 nonfunctioning adenomas, 42 prolactin-secreting adenomas, 32 growth hormone (GH)-secreting adenomas, 12 adrenocorticotropic hormone (ACTH)-secreting adenomas, and one thyrotropinsecreting adenoma) using the MPSIS, OUSAt, SONOPETt, and PAL-It systems. Bone window CT slices parallel to the transnasal surgical route provided direct visualization of the nasal anatomy for the approach. This method was helpful for determining the lateral extent of the sella floor requiring removal, especially in cases with previous surgeries [13]. Using MPSIS, typical soft adenomas could be dissected by rapid irrigation and removed by suction without injury to the normal pituitary gland. Slight tumor invasion in the cavernous sinus was obliterated by this system under direct vision in combination with micro-mirrors. Thus, pituitary adenomas could be selectively removed in all patients except those with extensive cavernous sinus invasion, with MPSIS. Fibrous adenomas, such as prolactin-secreting adenomas during dopamine agonist therapy or nonfunctioning adenomas found in subsequent surgery, were resected using the OUSAt or the SONOPETt systems. The PAL-It system was originally used to vaporize the thick mucosa and fibrous tissues in the nasal cavity and sphenoid sinus. Recently, it was used to vaporize the firm tumor tissue in the sella floor under direct vision. Firm adenomas could be reduced with the OUSAt, SONOPETt, and PAL-It systems. The pressures of aspiration, irrigation, and power of these devices were set accord-
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ing to the nature of the tumor. If the character of the tissues was in doubt, a biopsy of the tissue was performed and the tumor tissue was selectively resected. The sella floor was reconstructed with ceramics composed of a combination of hydroxyapatite and tricalcium phosphate, to facilitate additional surgery and drainage of cerebrospinal fluid leakage during surgery [14]. There was no surgical morbidity or mortality. 3.1. Representative cases 3.1.1. Patient 1: tumor removal with MPSIS A 30-year-old male presented with a sudden-onset headache and visual disturbance. He showed no typical physical symptoms of Cushing’s disease. Neurological examination showed blindness in the left eye and a defect of the lateral visual field in the right eye. A few hours later, he showed a left-sided cavernous sinus syndrome (exophthalmos, chemosis, and oculomotor nerve palsy). On endocrinological examination, serum ACTH and cortisol levels were markedly elevated. The basal levels of other hormones were within normal range. A magnetic resonance (MR) imaging revealed an intra- and suprasellar mass with a pituitary hemorrhage and extension of the hemorrhage to the anterior skull base (Fig. 5A). The tumor was successfully removed via the transnasal route by using MPSIS in combination with micro-mirrors. After surgery, the patient’s left-sided cavernous sinus syndrome and right-sided temporal hemianopsia were immediately resolved. Serum ACTH and cortisol levels declined to within normal range. Subsequent MR images revealed no tumor recurrence 3 years after surgery (Fig. 5B). 3.1.2. Patient 2: tumor resection with MPSIS and the SONOPETt system A 33-year-old female presented with bitemporal hemianopsia and acromegalic features. Preoperative serum GH and IGF-I levels were elevated. This patient had undergone transnasal exploration for a GH-secreting pituitary adenoma with left-sided cavernous sinus invasion. After surgery, serum GH and IGF-I levels were still elevated. An MR imaging demonstrated a residual adenoma in the left cavernous sinus. Treatments with dopamine agonist and octreotide were not effective. Gamma knife stereotactic radiosurgery was performed on the residual tumor 6 months after surgery. However, 4 months after radiosurgery, serum GH and IGF-I levels were still elevated. Another MR imaging showed regrowth of the residual tumor (Fig. 6A). This patient underwent a second transnasal pituitary exploration. This tumor, especially fibrous, was partially resected by using MPSIS and the SONOPETt system. After surgery, serum GH and IGF-I levels were slightly elevated. An additional MR imaging revealed a partial resection of the
A
B Fig. 5. Sagittal enhanced T1-weighted MR images at admission (A) and 3 years after surgery (B). (A) MR image showing an intra- and suprasellar mass with an acute pituitary hemorrhage and a hematoma extending to the anterior base of the skull. (B) MR image revealing no tumor recurrence.
residual tumor (Fig. 6B). This patient is receiving follow-up care without medical treatment. 3.1.3. Patient 3: tumor vaporization with the PAL-It system A 35-year-old male presented with hyperthyroidism and visual field defect. Physical examination noted acromegalic features. Endocrinological and radiological examinations revealed a thyrotropin-, GH-, and prolactin-secreting pituitary adenoma. After octreotide treatment for 1 month (300 µm/d), this patient underwent partial tumor removal via the sublabial transsphenoidal route at another hospital. After surgery, an MR imaging demonstrated a large intraand suprasellar residual tumor with right cavernous sinus invasion (Fig. 7A). Endocrinological examination revealed elevated serum thyrotropin, free-T3, free-T4, GH, IGF-I, and prolactin levels. A second transnasal pituitary surgery was performed. The thick mucosa and fibrous tissues in the nasal cavity and sphenoid sinus were vaporized using the PAL-It system. The tumor was especially fibrous and firm,
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A
B
B
Fig. 6. Coronal enhanced T1-weighted MR images 4 months after radiosurgery (A) and 2 weeks after secondary surgery (B). (A) MR image revealing regrowth of the residual tumor after radiosurgery. (B) MR image demonstrating partial resection of the residual fibrous tumor using MPSIS and SONOPETt.
Fig. 7. Sagittal enhanced T1-weighted MR images 1 year after the first transsphenoidal surgery (A) and 1 month after secondary transnasal surgery (B). (A) MR image showing a large, firm intra- and suprasellar residual tumor with the right-sided cavernous sinus invasion. (B) MR image revealing partial resection of the residual firm tumor using PAL-It.
and thus could not be resected by usual surgical instruments, MPSIS, or the SONOPETt system. The firm intrasellar lesion was vaporized using the PAL-It system after confirmation of tumor tissue type by a biopsy. Another MR imaging revealed a partial resection of the firm tumor after surgery (Fig. 7B).
References
4. Conclusions The suitability and usefulness of the MPSIS, ultrasonic surgical aspirators with needle-type probes, and the electromagnetic field system for direct transnasal pituitary exploration have been proven. With the advancement of surgical technique and development of surgical instruments, most pituitary adenomas can now be removed via the transnasal route.
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