Severe Hyperthermia, Hypernatremia, and Early Postoperative Death After Transethmoidal Cavitron Ultrasonic Surgical Aspirator (CUSA)‐Assisted Diencephalic Mass Removal in 4 Dogs and 2 Cats Dominic J. Marino1, DVM, Diplomate ACVS and ACCT, CCRP, Curtis W. Dewey1,2, DVM, MS, Diplomate ACVIM (Neurology) and ACVS, Catherine A. Loughin1, DVM, Diplomate ACVS and ACCT, and Leonard J. Marino1, MD, FAAP 1
Department of Surgery, Long Island Veterinary Specialists, Plainview, New York and Medicine, Cornell University, Ithaca, New York
Corresponding Author Dominic J. Marino, DVM, Long Island Veterinary Specialists, 163 South Service Road, Plainview, NY 11803. E‐mail: [email protected] Submitted January 2012 Accepted June 2012 DOI:10.1111/j.1532-950X.2014.12238.x
Department of Clinical Sciences, College of Veterinary
Objective: To report clinical findings including severe hyperthermia and hypernatremia after transethmoidal Cavitron ultrasonic surgical aspirator (CUSA)‐assisted diencephalic mass removal. Study Design: Retrospective case series. Animals: Dogs (n ¼ 4) and 2 cats. Methods: Medical records (1997–2003) of dogs and cats that had transethmoidal CUSA‐assisted diencephalic mass removal were reviewed. Retrieved data were: history, signalment, blood work, neurologic examination findings, MRI results, histopathology, postoperative complications, pre‐ and postoperative medical therapy, and outcome. Results: Tumor types included: meningioma (n ¼ 3), choroid plexus papilloma (1), astrocytoma (1), and pituitary macroadenoma (1). Median onset of hyperthermia was 3.5 hours (range: 1–6 hours) after extubation; median high temperature at onset was 40.3°C, (range: 39.6–41.7°C). Median onset of hypernatremia (median, 172 mmol/L; range: 168–196 mmol/L) was 4.5 hours (range: 1–9 hours) after extubation. Median time of death after hyperthermia was 10.5 hours (range: 6–13 hours) and after extubation was 13.5 hours (range: 11–15 hours). Conclusions: Transethmoidal CUSA‐assisted diencephalic mass removal is associated with early postoperative hyperthermia, hypernatremia, and death, and cannot be recommended.
Brain tumors in the diencephalic region are uncommon in both animals and people when compared with other tumor locations in the brain1–5; however, recognized similar tumor types include: pituitary adenoma, meningioma, choroid plexus adenoma, and ependymoma.1,3,4,6–9 Surgical exploration of the diencephalon is difficult because of limited viewing afforded by most approaches and the close proximity of vital vascular and neuroanatomic structures.6,7,10–15 Use of endoscopes in diencephalic surgery has increased16–19 and improved outcomes and safety of diencephalic surgery are most notable for transsphenoidal pituitary surgery in people.16,17,20–25 Despite these advances, the vulnerability of the hypothalamus during diencephalic surgery makes disturbances of hypothalamic origin such as electrolyte imbalances, hypothyroidism, and abnormal thermoregulation among the most common complications observed.5,9,26 Acute hyperthermia after suspected hypothalamic damage has been reported
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after stereotactic radiosurgery for pituitary adenoma in an adult male person.27 Diencephalic surgery in animals has its genesis in experimental hypophysectomy performed to study physiologic effects.8,28,29 Transsphenoidal hypophysectomy for treatment of canine and feline pituitary‐dependent hypercortisolism (PDH)7,8,12,13,30–34 and modifications including a transtemporal approach are reported.10,11,35 CT, MRI, improved surgical instrumentation and techniques, and standardized postoperative medical protocols have improved outcomes such that hypophysectomy is the preferred treatment for PDH.36 Immediate postoperative complications associated with transsphenoidal hypophysectomy include: hemorrhage, hypernatremia, dehydration, and glucocorticoid deficiency which can result in death.10,12,36–38 We are unaware of reports where temperature monitoring was described in detail after surgery and only 1 report describing “large temperature fluctuations” as
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Medical records (1997–2003) of dogs and cats with an MRI diagnosis of a diencephalic mass treated at Long Island Veterinary Specialists using transethmoidal CUSA‐assisted mass removal were eligible for inclusion. Retrieved data were: history; signalment; hematologic and serum biochemical profile; neurologic examination findings; MRI, thoracic radiography and histopathology findings; postoperative complications; pre‐ and postoperative medical therapy; and outcome. Neuroanatomic localization was confirmed with MRI.
gyrus using a # 11 surgical blade and electrocautery to enhance identification of the mass. Mass removal was achieved under 3 magnification using an expanded field telescope (Designs for Vision, Inc., Ronkonkoma, NY) and using an ultrasonic aspirator (CUSA; Excel, Covidien, Boulder, CO) with a 36‐kHz handpiece at the following settings: amplitude, 80%; aspiration, 20%; irrigation, 3 mL/min; and a power setting of 2þ, manual manipulation and suction. No major tissue damage to surrounding tissues was grossly evident after use of the CUSA. Vessels encountered were coagulated with bipolar cautery and residual hemorrhage controlled with gel foam sponge. The optic chiasm was not readily seen. Visible tumor and tissue suspected of being abnormal based on MRI findings was removed, and the empty cavity was lavaged with saline (0.9% NaCl) solution and without assisted pressure to remove debris and residual blood clots. The dural defect was not closed and the frontal bone plate was not replaced. The frontalis muscle and subcutaneous tissues were apposed with simple interrupted sutures of 3‐0 or 4‐0 polydioxanone suture material.
Anesthesia and Preoperative Preparation
Postoperative Care and Follow‐Up
After premedication with atropine (0.022–0.044 mg/kg subcutaneously) and hydromorphone (0.1 mg/kg subcutaneously), anesthesia was induced with propofol (3–6 mg/kg intravenously [IV]) and maintained with isoflurane in oxygen. Cefazolin (22 mg/kg IV) was administered at the beginning of surgery and every 90 minutes during surgery. Mannitol (0.5 g/kg IVover 10– 15 minutes) and prednisolone sodium succinate (30 mg/kg IV) were administered preoperatively. MRI scans (1.0 T scanner; Vista, Picker, Andover, MA) were performed within 7 days before surgery. Sagittal and axial T2‐weighted images, sagittal and axial T1‐weighted images with and without administration of IV gadolinium (Optimark, Jersey City, NJ) were obtained.
After recovery, animals were monitored in intensive care and administered isotonic fluids (0.45%NaCl/2.5% dextrose; 66 mL/kg/day IV) supplemented with 10 mEq potassium chloride/500 mL. Buprenorphine (0.3 mg/kg, IV every 8 hours) and cephalexin (22 mg/kg IV every 8 hours) were administered postoperatively. Temperature was monitored hourly, serum electrolytes (Vet Stat Electrolyte and Blood Gas Analyzer, Idexx, Westbrook, ME) and blood glucose concentration (Idexx Catalyst Dx) were analyzed at the onset of hyperthermia and repeated at the surgeon’s discretion. Reference intervals were: sodium (144–160 mmol/L); potassium (3.5–5.8 mmol/L); glucose (74–143 mg/dL); temperature (38.1–39.2°C). Prednisolone sodium succinate (Univet Pharmaceuticals, Milton, ON, Canada; 30 mg/kg IV) was administered 6 hours after the preoperative dose and prednisone was begun (0.5 mg/kg) every 12 hours subcutaneously in surviving animals. Desmopressin (DDAVP, Ferring Phamaceuticals, Parsippany, NJ) was administered (1 drop in each conjunctival sac twice daily).
a postoperative complication in 1 of 52 dogs after transsphenoidal hypophysectomy.7 Thus, our purpose was to describe severe hyperthermia after transethmoidal cavitron ultrasonic surgical aspirator (CUSA)‐assisted diencephalic mass removal in 4 dogs and 2 cats.
MATERIALS AND METHODS Case Selection and Data Retrieval
Surgical Technique Each animal was anesthetized for surgery as described above. The head was clipped from the caudal extent of the zygomatic arches to approximately the level of the infraorbital foramina. After positioning in sternal recumbency with the head and neck at an 90° angle to each other to facilitate observation of the rostral extent of the cribriform plate, the surgical site was aseptically prepared. One surgeon (D.J.M.) performed all surgical procedures. After transfrontal sinus craniotomy,39 the internal table of the frontal bone and the ethmoturbinates were removed using a rongeur to expose the meninges covering the olfactory bulbs and frontal lobe. Additional access to the olfactory and frontal region was achieved by resection of the cribriform bone plate. Care was taken during incision of the meninges to avoid lacerating the rostral extent of the dorsal sagittal sinus within the falx cerebri. Bleeding was minimal and was controlled with bipolar cautery and gel foam sponge. The left prefrontal region and olfactory bulb were amputated rostral to the precruciate
RESULTS Four dogs (Pomeranian, Labrador Retriever, American Staffordshire Terrier, Boxer) and 2 cats (domestic short hair breeds) with transethmoidal CUSA‐assisted diencephalic mass removal were identified. Mean age of dogs at surgery was 6.7 years (range: 5–8 years) and for cats was 9 years. There were 2 male castrated and 2 female spayed dogs, and 1 male castrated and 1 female spayed cat. Mean weight for dogs was 31.2 kg (range: 5.5–40.2 kg) and for cats, 4.2 kg (range: 4.1– 4.3 kg). Historical and clinical findings were consistent with forebrain dysfunction including vision loss (n ¼ 6), mental
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dullness, (2), circling (1), and seizures (1). None of the animals had been treated before admission and mean onset of clinical signs was 28 days (range: 4–60 days). Neuroanatomic localization based on MRI (Figs 1 and 2) and histopathology results are summarized (Table 1). Median preoperative temperature was 37.8°C (range: 37.3–38.1°C). Pre‐ and postoperative temperature values are provided (Fig 3). Median time of the onset of hyperthermia was 3.5 hours (range: 1–6 hours) after extubation with a median high temperature at the onset of hyperthermia of 40.3°C (range: 39.6–41.7°C). Median time of onset of the hypernatremia was 4.5 hours (range: 1–9 hours) after extubation with a median abnormal sodium level of 172 mmol/L (range: 168–196 mmol/L). Blood glucose and serum potassium levels were within the normal reference interval during postoperative monitoring in all animals. All animals died within 24 hours of extubation. Median time of death after hyperthermia was 10.5 hours (range: 6–13 hours). Median time of death after extubation was 13.5 hours (range: 11–15 hours), with 4 animals euthanatized at owner request because of the development of a comatose state indicative of loss of brain stem function. Necropsy was not permitted by the owners for any of the dogs or cats.
DISCUSSION Transethmoidal CUSA‐assisted diencephalic mass removal was associated with severe hyperthermia and death in the animals in this study. Because there was a variety of tumor types, an association with histopathology findings could not be assessed. Hypophysectomy using various approaches has been reported in animals8,10–13,19,30–36,38,40; however, only in a
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single study of 52 dogs having transsphenoidal hypophysectomy for PDH, did 1 dog experience “large temperature fluctuations” immediately after surgery.7 Although no specific cause was identified, damage to the hypothalamic thermoregulatory center was suspected. Damage to the diencephalic structures associated with hypophysectomy has been reported from a variety of causes including hemorrhage, surgical manipulation, hypernatremia, and CUSA application.7,11 Necropsy findings in the dog with thermal dysregulation that subsequently died, revealed a large hematoma in the area of the brain stem, as well as hemorrhage and fibrinoid necrosis of the hypothalamus.7 It was speculated that thermal dysregulation was the result of the damage to the hypothalamic thermoregulatory center. In our animals, the masses were all in close proximity to the hypothalamus and with the visual limitations of the transfrontal sinus approach, it is likely that iatrogenic direct trauma or secondary surgical edema contributed to hypothalamic dysregulation. Although hemorrhage was not considered marked at the time of surgery, postoperative hematoma formation in the region of the hypothalamus may have been a contributing factor. Uncontrolled postoperative bleeding may have occurred undetected; however, using a CUSA for the mass removal should have decreased the chance of hemorrhage. Hemorrhage within the CNS can lead to hyperthermia as well as oxygen free radical‐mediated parenchymal damage. In people with diencephalic mass removal, damage and edema to the hypothalamus can also be secondary to rapid decompression of a severely compressed hypothalamus.5,41–43 Several animals in our study had severe hypothalamic compression from the diencephalic mass and would be expected to experience some level of edema secondary to rapid decompression. Additionally, autopsy findings in people
Figure 1 Brain MRI of a 7‐year‐old Labrador (Case 1). Contrast was performed on a 1.0 T Picker Vista. T1‐weighted dorsal (A) and axial (B) images were acquired demonstrating a 1.9 cm 2.1 cm well delineated extra‐axial, uniformly contrast enhancing mass (arrow) found on the ventral floor of the calvarium. The mass extends from the caudal limits of the olfactory bulbs to the rostral diencephalon and crosses midline (TR ¼ 515, TE ¼ 14, slice thickness ¼ 2.5, gap ¼ 0, FOV ¼ 16, matrix ¼ 160 256).
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Figure 2 Brain MRI of a 9‐year‐old domestic shorthair (Case 6) was performed on a 1.0 T Picker Vista. T2‐weighted sagittal (A) and axial (B) images were acquired and demonstrated a 2.8 cm 1.7 cm intra‐axial, noncontrast enhancing well circumscribed intraventricular mass (arrow) affecting the third ventricle and mesencephalic aqueduct. The mass extends from the rostral diencephalon to the pons (TR ¼ 63‐4, TE ¼ 104, slice thickness ¼ 3.5, gap ¼ 0, FOV ¼ 13, matrix ¼ 144 256).
who experienced hypothalamic dysthermia after diencephalic surgery revealed bilaterally symmetrical hemorrhagic and infarcted foci in the anterior hypothalamus corresponding to compression.44,45 The lesions were reflective of the persistent edema, vascular stasis, and vascular collapse of the region. It was speculated that the neuronal stimulus responsible for temperature control would continue without input from the hypothalamus and thus without central and peripheral receptor feedback. Without this essential feedback, an entire temperature regulation system failure would occur.5,41–43 Median time of the onset of hyperthermia was 3.5 hours (range: 1–6 hours)
Table 1
after extubation, which is within the expected time span of hypothalamic damage from hemorrhage or edema. Median time of death after extubation was 13.5 hours (range: 11– 15 hours), which followed the episode of hyperthermia and was secondary to cardiac arrest (n ¼ 2) and or euthanasia at owner request because of the development of a comatose state indicative of loss of brain stem function (n ¼ 4). Surgery to remove masses or cysts of the walls of the third ventricle has been associated with thermoregulatory disorders in people.5,9,26,46 Although histologic findings on autopsy reflect glial lesions or colloid cysts without the establishment of
Signalment, MRI, and Histopathology Findings for 4 Dogs and 2 Cats That Had Transethmoidal Diencephalic Mass Removal
Case
Age
Breed
1
7 years
Labrador
2
3 years, 10 months
American Stafford‐shire Terrier
3
6 years
Boxer
4
6 years, 2 months
Pomeranian
5
8 years, 2 months
DSH
6
9 years, 2 months
DSH
MR Localization
Size
Extra‐axial contrast enhancing mass on the ventral floor of the calvarium, extending from the caudal limits of the olfactory bulbs to the rostral diencephalon and crossing midline Intra‐axial, contrast enhancing diencephalic mass within the dorsal aspect of the third ventricle, compressing both lateral ventricles Well delineated extra‐axial, contrast enhancing midline mass extending from the caudal limits of the olfactory bulbs to the pituitary Ventral extra‐axial, contrast enhancing diencephalic mass in the region of the pituitary Extra‐axial, contrast enhancing ventral midline diencephalic mass Intra‐axial, noncontrast enhancing intraventricular mass extending from the rostral diencephalon to the pons
1.9 cm 2.1 cm
Meningioma
2.2 cm 2.9 cm
Choroid plexus papilloma
1.6 cm 1.8 cm
Meningioma
1.1 cm 1.0 cm
Pituitary macroadenoma
2.1 cm 1.9 cm
Meningioma
2.8 cm 1.7 cm
Astrocytoma
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Figure 3
Preoperative, operative, and postoperative body temperatures in 4 dogs and 2 cats that had transethmoidal diencephalic mass removal.
a firm etiopathogenesis, surgery in this region frequently results in widespread impairment of hypothalamic function.5,47–49 In one study of human patients with mass removal associated with the third ventricle, the greatest elevations in temperature after surgery were seen in people with larger and or more posteriorly located masses.5 These clinical findings were consistent with those of the dog that had a large third ventricle associated mass. Electrolyte imbalances are well documented in both animal patients having transsphenoidal hypophysectomy for PDH and people having diencephalic surgery and have been attributed to insufficient fluid intake before, during, and after surgery and an acute deficiency of arginine vasopressin.5–8,11–13,26,28,31–34,37,50 Once recognized and with early intervention including correction of the deficits with supplementation with DDAVP, administration of a low sodium fluid, and initiation of oral intake of fluids as soon as possible, restoration of the normal physiologic state may occur.5,8 Although it is possible that severe electrolyte imbalances could result in neuronal edema sufficient to cause hypothalamic damage, it has been reported in people that electrolyte imbalances, in conjunction with other forms of
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hypothalamic dysregulation (i.e., dysthermia), if severe and persistent, are indicative of wide spread hypothalamic damage and inevitable hypothalamic regulatory collapse.5 Median time of the onset of hyperthermia was 3.5 hours (range: 1–6 hours), and 4.5 hours (range: 1–9 hours) for hypernatremia after extubation. All animals in our study had electrolyte imbalances subsequent to development of refractory hyperthermia indicative of damage to the thermoregulatory center preceding the ensuing widespread hypothalamic damage. Successful application of the CUSA in brain surgery has been reported in veterinary and human patients; however, power settings have been shown to affect the degree of damage to surrounding tissues.51–53 CUSA enables the surgeon to ablate tissue high in water content (some tumors) while sparing tissue that is low in water content (vessels and nerves). The CUSA has a tip that vibrates at various frequencies and fragments tissue while simultaneously lavaging and aspirating material from the surgical field. This results in less hemorrhage and improved visibility, allowing for more extensive tumor removal with a higher margin of safety in highly vascular or anatomically sensitive regions.51–54 In our surgical procedures, settings were based on the lowest power needed to liquefy and
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remove the abnormal tissue. Although this basis for CUSA power settings has been previously described,11 it is possible that the hypothalamus sustained collateral CUSA‐related damage. There are several limitations to this retrospective study including the low case number and lack of owner permission for necropsy to confirm cause of death and extent of hypothalamic injury. Although the exact mechanism of hypothalamic injury cannot be determined, hypothalamic injury is likely to be responsible for the hypothalamic regulatory collapse and the ultimate cause of death in these animals. Based on our results, transethmoidal CUSA‐assisted diencephalic mass removal cannot be recommended. Any future attempts at surgical removal of large diencephalic tumors should include more intensive intra‐ and postoperative temperature and electrolyte monitoring than we used. Although the combination of electrolyte imbalances and dysthermia have been associated with wide spread hypothalamic damage and death in human patients, further study is warranted in veterinary patients. Data regarding the effect of CUSA on the hypothalamus in animals having diencephalic surgery will be necessary to develop guidelines for its use.
9. Lipton J: Thermoregulatory disorders after removal of a craniopharyngioma from the third ventricle. Brain Res Bull 1981;7:369–373 10. Niebauer GW, Evans SM: Transsphenoidal hypophysectomy in the dog. A new technique. Vet Surg 1988;17:296–303 11. Axlund TW, Behrend EN, Sorjonen DC, et al: Canine hypophysectomy using a ventral paramedian approach. Vet Surg 2005;34:179–189 12. Meij BP, Voorhout G, van der Ingh TS, et al: Transsphenoidal hypophysectomy in beagle dogs: evaluation of a microsurgical technique. Vet Surg 1997;26:295–309 13. Meij BP, Voorhout G, van der Ingh TS, et al: Transsphenoidal hypophysectomy for treatment of pituitary‐dependent hyperadrenocorticism in 7 cats. Vet Surg 2001;30:72–86 14. Tan LK, Jones RA: Nasal complications of the direct transnasal approach to the pituitary fossa. Br J Neurosurg 1995;9:739– 742 15. Pergolizzi RS, Jr., Nabavi A, Schwartz RB, et al: Intra‐operative MR guidance during trans‐sphenoidal pituitary resection: preliminary results. J Magn Reson Imaging 2001;13:136–141 16. Gardner PA, Prevedello DM, Kassam AB, et al: The evolution of the endonasal approach for craniopharyngiomas. J Neurosurg 2008;108:1043–1047
DISCLOSURE
17. Jho HD, Carrau RL: Endoscopic endonasal transsphenoidal surgery: experience with 50 patients. J Neurosurg 1997;87: 44–51
The authors report no financial or other conflicts related to this report.
18. Jho HD, Carrau RL, Ko Y, et al: Endoscopic pituitary surgery: an early experience. Surg Neurol 1997;47:213–222;discussion 222– 223
REFERENCES
19. Klopp LS, Rao S: Endoscopic‐assisted intracranial tumor removal in dogs and cats: long‐term outcome of 39 cases. J Vet Intern Med 2009;23:108–115
1. Koblik PD, LeCouteur RA, Higgins RJ, et al: CT‐guided brain biopsy using a modified Pelorus Mark III stereotactic system: experience with 50 dogs. Vet Radiol Ultrasound 1999;40:434–440 2. Koblik PD, LeCouteur RA, Higgins RJ, et al: Modification and application of a Pelorus Mark III stereotactic system for CT‐ guided brain biopsy in 50 dogs. Vet Radiol Ultrasound 1999;40:424–433 3. Moissonnier P, Blot S, Devauchelle P, et al: Stereotactic CT‐ guided brain biopsy in the dog. J Small Anim Pract 2002;43: 115–123 4. Sawin P, Hichon PW, Follett KA, et al: Computed imaging‐ assisted stereotactic brain biopsy: a risk analysis of 225 consecutive cases. Surg Neurol 1998;49:640–649 5. Clar HE: Clinical and morphological studies of pituitary and diencephalic space‐occupying lesions before and after operation, with special reference to temperature regulation. Acta Neurochir 1979;50:153–199
20. Sanai N, Quinones‐Hinojosa A, Narvid J, et al: Safety and efficacy of the direct endonasal transsphenoidal approach for challenging sellar tumors. J Neurooncology 2008;87:317–325 21. Bhatki AM, Carrau RL, Snyderman JH, et al: Endonasal surgery of the ventral skull base—Endoscopic transcranial surgery. Oral Maxillofac Surg Clin North Am 2010;22:157–168 22. Cavallo LM, Prevedello DM, Solari D, et al: Extended endoscopic endonasal transsphenoidal approach for residual or recurrent craniopharyngiomas. J Neurosurg 2009;111:578–589 23. Gardner PA, Kassam AB, Rothfus WE, et al: Preoperative and intraoperative imaging for endoscopic endonasal approaches to the skull base. Otolaryngol Clin North Am 2008;41:215– 230 24. Gardner PA, Kassam AB, Snyderman CH, et al: Outcomes following endoscopic, expanded endonasal resection of suprasellar craniopharyngiomas: a case series. J Neurosurg 2008;109:6–16
6. Konovalov A: Microsurgery of tumors of diencephalic region. Neurosurg Rev 1983;6:37–41
25. Gardner PA, Kassam AB, Thomas A, et al: Endoscopic endonasal resection of anterior cranial base meningiomas. Neurosurgery 2008;63:36–52;discussion 52–54
7. Meij BP, Voorhout G, van der Ingh TS, et al: Results of transsphenoidal hypophysectomy in 52 dogs with pituitary‐ dependent hyperadrenocorticism. Vet Surg 1998;27:246–261
26. Chatzisotiriou A, Selviaridis P, Kontopoulos V: Delayed persistent hyperthermia after resection of a craniophayngioma. Pediatr Neurosurg 2004;40:196–202
8. Meij BP: Hypophysectomy as a treatment for canine and feline Cushing’s disease. Vet Clin North Am Small Anim Pract 2001;31:1015–1041
27. Kalapurakal JA, Silverman CA, Akhtar N, et al: Acute hyperthermia following stereotactic radiosurgery for pituitary adenoma. Br J Radiol 1999;72:1218–1221
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Hyperthermia After Transethmoidal CUSA‐Assisted Diencephalic Mass Removal
28. Laws ER, Jr.: Functional pituitary tumors. The neurosurgeon and neuroendocrinology. Clin Neurosurg 1980;27:3–18 29. Liu JK, Das K, Weiss MH, et al: The history and evolution of transsphenoidal surgery. J Neurosurg 2001;95:1083–1096 30. Meij BP, Auriemma E, Grinwis G, et al: Successful treatment of acromegaly in a diabetic cat with transsphenoidal hypophysectomy. J Feline Med Surg 2010;12:406–410 31. Meij BP, Mol JA, Bevers MM, et al: Residual pituitary function after transsphenoidal hypophysectomy in dogs with pituitary‐ dependent hyperadrenocorticism. J Endocrinol 1997;155:531– 539 32. Meij BP, Mol JA, Bevers MM, et al: Alterations in anterior pituitary function of dogs with pituitary‐dependent hyperadrenocorticism. J Endocrinol 1997;154:505–512 33. Meij BP, Mol JA, Hazewinkel HA, et al: Assessment of a combined anterior pituitary function test in beagle dogs: rapid sequential intravenous administration of four hypothalamic releasing hormones. Domest Anim Endocrinol 1996;13:161– 170
Marino et al.
40. Yoshikawa H, Oda Y, Sakajiri K, et al: Pure akinesia manifested neuroleptic malignant syndrome: a clinical variant of progressive supranuclear palsy. Acta Neuropathol (Berl) 1997;93:306–309 41. Carmel P: Surgical syndromes of the hypothalamus. Clin Neurosurg 1979;25:133–159 42. Branch E, Burger P, Brewer D: Hypothermia in a case of hypothalamic infarction and sarcoidosis. Arch Neurol 1971;25:245–255 43. Killefer F, Stern W: Chronic effects of hypothalamic injury. Arch Neurol 1970;22:419–429 44. Addy P, Hudson F: Diencephalic syndrome of infantile emaciation. Arch Dis Child 1972;47:339–343 45. Pelc S: The diencephalic syndrome in infants. Eur Neurol 1972;7:321–334 46. Davison C: Disturbances of temperature regulation in man, in The hypothalamus and central levels of autonomic regulation. New York, NY, 1940, pp 774–823 47. Ciric J, Zivin J: Neuroepithelial (colloid) cysts of the septum pellucidum. J Neurosurg 1975;43:69–73
34. Meij BP, Mol JA, van der Ingh TS, et al: Assessment of pituitary function after transsphenoidal hypophysectomy in beagle dogs. Domest Anim Endocrinol 1997;14:81–97
48. Little J, Carty CM: Colloid cysts of the third ventricle. J Neurosurg 1974;39:230–235
35. Kendrick M, Silverberg G: Transtemporal hypophysectomy in the dog. Surg Neurol 1975;4:244–246
49. Stein B, Frasier R, Tenner M: Tumors of the third ventricle. J Neurol Neurosurg 1972;35:776–788
36. Meij B, Voorhout G, Rijnberk A: Progress in transsphenoidal hypophysectomy for treatment of pituitary‐dependent hyperadrenocorticism in dogs and cats. Mol Cell Endocrinol 2002;197:89–96
50. Hanson JM, Teske E, Voorthout G, et al: Prognostic factors for outcome after transsphenoidal hypophysectomy in dogs with pituitary‐dependent hyperadrenocorticism. J Neurosurg 2007;107:830–840
37. Hanson JM, Voorhout G, Teske E, et al: Efficacy of transsphenoidal hypophysectomy in treatment of dogs with pituitary‐dependent hyperadrenocorticism. J Vet Intern Med 2005;19:687–694
51. Greco JJ, Aiken SA, Berg JM, et al: Evaluation of intracranial meningioma resection with a surgical aspirator in dogs: 17 cases (1996–2004). J Am Vet Med Assoc 2006;229:394–400
38. Lantz GC, Ihle SL, Nelson RW, et al: Transsphenoidal hypophysectomy in the clinically normal dog. Am J Vet Res 1988;49:1134–1142 39. Glass EN, Kapatkin A, Vite C, et al: A modified bilateral transfrontal sinus approach to the canine frontal lobe and olfactory bulb: surgical technique and five cases. J Am Anim Hosp Assoc 2000;36:43–50
894
52. Yamasaki T, Moritake K, Nagai H: A new miniature ultrasonic surgical aspirator with a handpiece designed for transsphenoidal surgery. J Neurosurg 2003;99:177–179 53. Luis E, Gutmann D: Meningioma. Curr Opin Neurol 2004;17:687–692 54. Bagley R, Harrington M, Gay J: Effects of changes in power setting of an ultrasonic aspirator on amount of damage to the cerebral cortex of healthy dogs. Am J Vet Res 2001;62:248–251
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Department of Surgery, Long Island Veterinary Specialists, Plainview, New York and Medicine, Cornell University, Ithaca, New York
Corresponding Author Dominic J. Marino, DVM, Long Island Veterinary Specialists, 163 South Service Road, Plainview, NY 11803. E‐mail: [email protected] Submitted January 2012 Accepted June 2012 DOI:10.1111/j.1532-950X.2014.12238.x
Department of Clinical Sciences, College of Veterinary
Objective: To report clinical findings including severe hyperthermia and hypernatremia after transethmoidal Cavitron ultrasonic surgical aspirator (CUSA)‐assisted diencephalic mass removal. Study Design: Retrospective case series. Animals: Dogs (n ¼ 4) and 2 cats. Methods: Medical records (1997–2003) of dogs and cats that had transethmoidal CUSA‐assisted diencephalic mass removal were reviewed. Retrieved data were: history, signalment, blood work, neurologic examination findings, MRI results, histopathology, postoperative complications, pre‐ and postoperative medical therapy, and outcome. Results: Tumor types included: meningioma (n ¼ 3), choroid plexus papilloma (1), astrocytoma (1), and pituitary macroadenoma (1). Median onset of hyperthermia was 3.5 hours (range: 1–6 hours) after extubation; median high temperature at onset was 40.3°C, (range: 39.6–41.7°C). Median onset of hypernatremia (median, 172 mmol/L; range: 168–196 mmol/L) was 4.5 hours (range: 1–9 hours) after extubation. Median time of death after hyperthermia was 10.5 hours (range: 6–13 hours) and after extubation was 13.5 hours (range: 11–15 hours). Conclusions: Transethmoidal CUSA‐assisted diencephalic mass removal is associated with early postoperative hyperthermia, hypernatremia, and death, and cannot be recommended.
Brain tumors in the diencephalic region are uncommon in both animals and people when compared with other tumor locations in the brain1–5; however, recognized similar tumor types include: pituitary adenoma, meningioma, choroid plexus adenoma, and ependymoma.1,3,4,6–9 Surgical exploration of the diencephalon is difficult because of limited viewing afforded by most approaches and the close proximity of vital vascular and neuroanatomic structures.6,7,10–15 Use of endoscopes in diencephalic surgery has increased16–19 and improved outcomes and safety of diencephalic surgery are most notable for transsphenoidal pituitary surgery in people.16,17,20–25 Despite these advances, the vulnerability of the hypothalamus during diencephalic surgery makes disturbances of hypothalamic origin such as electrolyte imbalances, hypothyroidism, and abnormal thermoregulation among the most common complications observed.5,9,26 Acute hyperthermia after suspected hypothalamic damage has been reported
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after stereotactic radiosurgery for pituitary adenoma in an adult male person.27 Diencephalic surgery in animals has its genesis in experimental hypophysectomy performed to study physiologic effects.8,28,29 Transsphenoidal hypophysectomy for treatment of canine and feline pituitary‐dependent hypercortisolism (PDH)7,8,12,13,30–34 and modifications including a transtemporal approach are reported.10,11,35 CT, MRI, improved surgical instrumentation and techniques, and standardized postoperative medical protocols have improved outcomes such that hypophysectomy is the preferred treatment for PDH.36 Immediate postoperative complications associated with transsphenoidal hypophysectomy include: hemorrhage, hypernatremia, dehydration, and glucocorticoid deficiency which can result in death.10,12,36–38 We are unaware of reports where temperature monitoring was described in detail after surgery and only 1 report describing “large temperature fluctuations” as
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Medical records (1997–2003) of dogs and cats with an MRI diagnosis of a diencephalic mass treated at Long Island Veterinary Specialists using transethmoidal CUSA‐assisted mass removal were eligible for inclusion. Retrieved data were: history; signalment; hematologic and serum biochemical profile; neurologic examination findings; MRI, thoracic radiography and histopathology findings; postoperative complications; pre‐ and postoperative medical therapy; and outcome. Neuroanatomic localization was confirmed with MRI.
gyrus using a # 11 surgical blade and electrocautery to enhance identification of the mass. Mass removal was achieved under 3 magnification using an expanded field telescope (Designs for Vision, Inc., Ronkonkoma, NY) and using an ultrasonic aspirator (CUSA; Excel, Covidien, Boulder, CO) with a 36‐kHz handpiece at the following settings: amplitude, 80%; aspiration, 20%; irrigation, 3 mL/min; and a power setting of 2þ, manual manipulation and suction. No major tissue damage to surrounding tissues was grossly evident after use of the CUSA. Vessels encountered were coagulated with bipolar cautery and residual hemorrhage controlled with gel foam sponge. The optic chiasm was not readily seen. Visible tumor and tissue suspected of being abnormal based on MRI findings was removed, and the empty cavity was lavaged with saline (0.9% NaCl) solution and without assisted pressure to remove debris and residual blood clots. The dural defect was not closed and the frontal bone plate was not replaced. The frontalis muscle and subcutaneous tissues were apposed with simple interrupted sutures of 3‐0 or 4‐0 polydioxanone suture material.
Anesthesia and Preoperative Preparation
Postoperative Care and Follow‐Up
After premedication with atropine (0.022–0.044 mg/kg subcutaneously) and hydromorphone (0.1 mg/kg subcutaneously), anesthesia was induced with propofol (3–6 mg/kg intravenously [IV]) and maintained with isoflurane in oxygen. Cefazolin (22 mg/kg IV) was administered at the beginning of surgery and every 90 minutes during surgery. Mannitol (0.5 g/kg IVover 10– 15 minutes) and prednisolone sodium succinate (30 mg/kg IV) were administered preoperatively. MRI scans (1.0 T scanner; Vista, Picker, Andover, MA) were performed within 7 days before surgery. Sagittal and axial T2‐weighted images, sagittal and axial T1‐weighted images with and without administration of IV gadolinium (Optimark, Jersey City, NJ) were obtained.
After recovery, animals were monitored in intensive care and administered isotonic fluids (0.45%NaCl/2.5% dextrose; 66 mL/kg/day IV) supplemented with 10 mEq potassium chloride/500 mL. Buprenorphine (0.3 mg/kg, IV every 8 hours) and cephalexin (22 mg/kg IV every 8 hours) were administered postoperatively. Temperature was monitored hourly, serum electrolytes (Vet Stat Electrolyte and Blood Gas Analyzer, Idexx, Westbrook, ME) and blood glucose concentration (Idexx Catalyst Dx) were analyzed at the onset of hyperthermia and repeated at the surgeon’s discretion. Reference intervals were: sodium (144–160 mmol/L); potassium (3.5–5.8 mmol/L); glucose (74–143 mg/dL); temperature (38.1–39.2°C). Prednisolone sodium succinate (Univet Pharmaceuticals, Milton, ON, Canada; 30 mg/kg IV) was administered 6 hours after the preoperative dose and prednisone was begun (0.5 mg/kg) every 12 hours subcutaneously in surviving animals. Desmopressin (DDAVP, Ferring Phamaceuticals, Parsippany, NJ) was administered (1 drop in each conjunctival sac twice daily).
a postoperative complication in 1 of 52 dogs after transsphenoidal hypophysectomy.7 Thus, our purpose was to describe severe hyperthermia after transethmoidal cavitron ultrasonic surgical aspirator (CUSA)‐assisted diencephalic mass removal in 4 dogs and 2 cats.
MATERIALS AND METHODS Case Selection and Data Retrieval
Surgical Technique Each animal was anesthetized for surgery as described above. The head was clipped from the caudal extent of the zygomatic arches to approximately the level of the infraorbital foramina. After positioning in sternal recumbency with the head and neck at an 90° angle to each other to facilitate observation of the rostral extent of the cribriform plate, the surgical site was aseptically prepared. One surgeon (D.J.M.) performed all surgical procedures. After transfrontal sinus craniotomy,39 the internal table of the frontal bone and the ethmoturbinates were removed using a rongeur to expose the meninges covering the olfactory bulbs and frontal lobe. Additional access to the olfactory and frontal region was achieved by resection of the cribriform bone plate. Care was taken during incision of the meninges to avoid lacerating the rostral extent of the dorsal sagittal sinus within the falx cerebri. Bleeding was minimal and was controlled with bipolar cautery and gel foam sponge. The left prefrontal region and olfactory bulb were amputated rostral to the precruciate
RESULTS Four dogs (Pomeranian, Labrador Retriever, American Staffordshire Terrier, Boxer) and 2 cats (domestic short hair breeds) with transethmoidal CUSA‐assisted diencephalic mass removal were identified. Mean age of dogs at surgery was 6.7 years (range: 5–8 years) and for cats was 9 years. There were 2 male castrated and 2 female spayed dogs, and 1 male castrated and 1 female spayed cat. Mean weight for dogs was 31.2 kg (range: 5.5–40.2 kg) and for cats, 4.2 kg (range: 4.1– 4.3 kg). Historical and clinical findings were consistent with forebrain dysfunction including vision loss (n ¼ 6), mental
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dullness, (2), circling (1), and seizures (1). None of the animals had been treated before admission and mean onset of clinical signs was 28 days (range: 4–60 days). Neuroanatomic localization based on MRI (Figs 1 and 2) and histopathology results are summarized (Table 1). Median preoperative temperature was 37.8°C (range: 37.3–38.1°C). Pre‐ and postoperative temperature values are provided (Fig 3). Median time of the onset of hyperthermia was 3.5 hours (range: 1–6 hours) after extubation with a median high temperature at the onset of hyperthermia of 40.3°C (range: 39.6–41.7°C). Median time of onset of the hypernatremia was 4.5 hours (range: 1–9 hours) after extubation with a median abnormal sodium level of 172 mmol/L (range: 168–196 mmol/L). Blood glucose and serum potassium levels were within the normal reference interval during postoperative monitoring in all animals. All animals died within 24 hours of extubation. Median time of death after hyperthermia was 10.5 hours (range: 6–13 hours). Median time of death after extubation was 13.5 hours (range: 11–15 hours), with 4 animals euthanatized at owner request because of the development of a comatose state indicative of loss of brain stem function. Necropsy was not permitted by the owners for any of the dogs or cats.
DISCUSSION Transethmoidal CUSA‐assisted diencephalic mass removal was associated with severe hyperthermia and death in the animals in this study. Because there was a variety of tumor types, an association with histopathology findings could not be assessed. Hypophysectomy using various approaches has been reported in animals8,10–13,19,30–36,38,40; however, only in a
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single study of 52 dogs having transsphenoidal hypophysectomy for PDH, did 1 dog experience “large temperature fluctuations” immediately after surgery.7 Although no specific cause was identified, damage to the hypothalamic thermoregulatory center was suspected. Damage to the diencephalic structures associated with hypophysectomy has been reported from a variety of causes including hemorrhage, surgical manipulation, hypernatremia, and CUSA application.7,11 Necropsy findings in the dog with thermal dysregulation that subsequently died, revealed a large hematoma in the area of the brain stem, as well as hemorrhage and fibrinoid necrosis of the hypothalamus.7 It was speculated that thermal dysregulation was the result of the damage to the hypothalamic thermoregulatory center. In our animals, the masses were all in close proximity to the hypothalamus and with the visual limitations of the transfrontal sinus approach, it is likely that iatrogenic direct trauma or secondary surgical edema contributed to hypothalamic dysregulation. Although hemorrhage was not considered marked at the time of surgery, postoperative hematoma formation in the region of the hypothalamus may have been a contributing factor. Uncontrolled postoperative bleeding may have occurred undetected; however, using a CUSA for the mass removal should have decreased the chance of hemorrhage. Hemorrhage within the CNS can lead to hyperthermia as well as oxygen free radical‐mediated parenchymal damage. In people with diencephalic mass removal, damage and edema to the hypothalamus can also be secondary to rapid decompression of a severely compressed hypothalamus.5,41–43 Several animals in our study had severe hypothalamic compression from the diencephalic mass and would be expected to experience some level of edema secondary to rapid decompression. Additionally, autopsy findings in people
Figure 1 Brain MRI of a 7‐year‐old Labrador (Case 1). Contrast was performed on a 1.0 T Picker Vista. T1‐weighted dorsal (A) and axial (B) images were acquired demonstrating a 1.9 cm 2.1 cm well delineated extra‐axial, uniformly contrast enhancing mass (arrow) found on the ventral floor of the calvarium. The mass extends from the caudal limits of the olfactory bulbs to the rostral diencephalon and crosses midline (TR ¼ 515, TE ¼ 14, slice thickness ¼ 2.5, gap ¼ 0, FOV ¼ 16, matrix ¼ 160 256).
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Figure 2 Brain MRI of a 9‐year‐old domestic shorthair (Case 6) was performed on a 1.0 T Picker Vista. T2‐weighted sagittal (A) and axial (B) images were acquired and demonstrated a 2.8 cm 1.7 cm intra‐axial, noncontrast enhancing well circumscribed intraventricular mass (arrow) affecting the third ventricle and mesencephalic aqueduct. The mass extends from the rostral diencephalon to the pons (TR ¼ 63‐4, TE ¼ 104, slice thickness ¼ 3.5, gap ¼ 0, FOV ¼ 13, matrix ¼ 144 256).
who experienced hypothalamic dysthermia after diencephalic surgery revealed bilaterally symmetrical hemorrhagic and infarcted foci in the anterior hypothalamus corresponding to compression.44,45 The lesions were reflective of the persistent edema, vascular stasis, and vascular collapse of the region. It was speculated that the neuronal stimulus responsible for temperature control would continue without input from the hypothalamus and thus without central and peripheral receptor feedback. Without this essential feedback, an entire temperature regulation system failure would occur.5,41–43 Median time of the onset of hyperthermia was 3.5 hours (range: 1–6 hours)
Table 1
after extubation, which is within the expected time span of hypothalamic damage from hemorrhage or edema. Median time of death after extubation was 13.5 hours (range: 11– 15 hours), which followed the episode of hyperthermia and was secondary to cardiac arrest (n ¼ 2) and or euthanasia at owner request because of the development of a comatose state indicative of loss of brain stem function (n ¼ 4). Surgery to remove masses or cysts of the walls of the third ventricle has been associated with thermoregulatory disorders in people.5,9,26,46 Although histologic findings on autopsy reflect glial lesions or colloid cysts without the establishment of
Signalment, MRI, and Histopathology Findings for 4 Dogs and 2 Cats That Had Transethmoidal Diencephalic Mass Removal
Case
Age
Breed
1
7 years
Labrador
2
3 years, 10 months
American Stafford‐shire Terrier
3
6 years
Boxer
4
6 years, 2 months
Pomeranian
5
8 years, 2 months
DSH
6
9 years, 2 months
DSH
MR Localization
Size
Extra‐axial contrast enhancing mass on the ventral floor of the calvarium, extending from the caudal limits of the olfactory bulbs to the rostral diencephalon and crossing midline Intra‐axial, contrast enhancing diencephalic mass within the dorsal aspect of the third ventricle, compressing both lateral ventricles Well delineated extra‐axial, contrast enhancing midline mass extending from the caudal limits of the olfactory bulbs to the pituitary Ventral extra‐axial, contrast enhancing diencephalic mass in the region of the pituitary Extra‐axial, contrast enhancing ventral midline diencephalic mass Intra‐axial, noncontrast enhancing intraventricular mass extending from the rostral diencephalon to the pons
1.9 cm 2.1 cm
Meningioma
2.2 cm 2.9 cm
Choroid plexus papilloma
1.6 cm 1.8 cm
Meningioma
1.1 cm 1.0 cm
Pituitary macroadenoma
2.1 cm 1.9 cm
Meningioma
2.8 cm 1.7 cm
Astrocytoma
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Figure 3
Preoperative, operative, and postoperative body temperatures in 4 dogs and 2 cats that had transethmoidal diencephalic mass removal.
a firm etiopathogenesis, surgery in this region frequently results in widespread impairment of hypothalamic function.5,47–49 In one study of human patients with mass removal associated with the third ventricle, the greatest elevations in temperature after surgery were seen in people with larger and or more posteriorly located masses.5 These clinical findings were consistent with those of the dog that had a large third ventricle associated mass. Electrolyte imbalances are well documented in both animal patients having transsphenoidal hypophysectomy for PDH and people having diencephalic surgery and have been attributed to insufficient fluid intake before, during, and after surgery and an acute deficiency of arginine vasopressin.5–8,11–13,26,28,31–34,37,50 Once recognized and with early intervention including correction of the deficits with supplementation with DDAVP, administration of a low sodium fluid, and initiation of oral intake of fluids as soon as possible, restoration of the normal physiologic state may occur.5,8 Although it is possible that severe electrolyte imbalances could result in neuronal edema sufficient to cause hypothalamic damage, it has been reported in people that electrolyte imbalances, in conjunction with other forms of
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hypothalamic dysregulation (i.e., dysthermia), if severe and persistent, are indicative of wide spread hypothalamic damage and inevitable hypothalamic regulatory collapse.5 Median time of the onset of hyperthermia was 3.5 hours (range: 1–6 hours), and 4.5 hours (range: 1–9 hours) for hypernatremia after extubation. All animals in our study had electrolyte imbalances subsequent to development of refractory hyperthermia indicative of damage to the thermoregulatory center preceding the ensuing widespread hypothalamic damage. Successful application of the CUSA in brain surgery has been reported in veterinary and human patients; however, power settings have been shown to affect the degree of damage to surrounding tissues.51–53 CUSA enables the surgeon to ablate tissue high in water content (some tumors) while sparing tissue that is low in water content (vessels and nerves). The CUSA has a tip that vibrates at various frequencies and fragments tissue while simultaneously lavaging and aspirating material from the surgical field. This results in less hemorrhage and improved visibility, allowing for more extensive tumor removal with a higher margin of safety in highly vascular or anatomically sensitive regions.51–54 In our surgical procedures, settings were based on the lowest power needed to liquefy and
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remove the abnormal tissue. Although this basis for CUSA power settings has been previously described,11 it is possible that the hypothalamus sustained collateral CUSA‐related damage. There are several limitations to this retrospective study including the low case number and lack of owner permission for necropsy to confirm cause of death and extent of hypothalamic injury. Although the exact mechanism of hypothalamic injury cannot be determined, hypothalamic injury is likely to be responsible for the hypothalamic regulatory collapse and the ultimate cause of death in these animals. Based on our results, transethmoidal CUSA‐assisted diencephalic mass removal cannot be recommended. Any future attempts at surgical removal of large diencephalic tumors should include more intensive intra‐ and postoperative temperature and electrolyte monitoring than we used. Although the combination of electrolyte imbalances and dysthermia have been associated with wide spread hypothalamic damage and death in human patients, further study is warranted in veterinary patients. Data regarding the effect of CUSA on the hypothalamus in animals having diencephalic surgery will be necessary to develop guidelines for its use.
9. Lipton J: Thermoregulatory disorders after removal of a craniopharyngioma from the third ventricle. Brain Res Bull 1981;7:369–373 10. Niebauer GW, Evans SM: Transsphenoidal hypophysectomy in the dog. A new technique. Vet Surg 1988;17:296–303 11. Axlund TW, Behrend EN, Sorjonen DC, et al: Canine hypophysectomy using a ventral paramedian approach. Vet Surg 2005;34:179–189 12. Meij BP, Voorhout G, van der Ingh TS, et al: Transsphenoidal hypophysectomy in beagle dogs: evaluation of a microsurgical technique. Vet Surg 1997;26:295–309 13. Meij BP, Voorhout G, van der Ingh TS, et al: Transsphenoidal hypophysectomy for treatment of pituitary‐dependent hyperadrenocorticism in 7 cats. Vet Surg 2001;30:72–86 14. Tan LK, Jones RA: Nasal complications of the direct transnasal approach to the pituitary fossa. Br J Neurosurg 1995;9:739– 742 15. Pergolizzi RS, Jr., Nabavi A, Schwartz RB, et al: Intra‐operative MR guidance during trans‐sphenoidal pituitary resection: preliminary results. J Magn Reson Imaging 2001;13:136–141 16. Gardner PA, Prevedello DM, Kassam AB, et al: The evolution of the endonasal approach for craniopharyngiomas. J Neurosurg 2008;108:1043–1047
DISCLOSURE
17. Jho HD, Carrau RL: Endoscopic endonasal transsphenoidal surgery: experience with 50 patients. J Neurosurg 1997;87: 44–51
The authors report no financial or other conflicts related to this report.
18. Jho HD, Carrau RL, Ko Y, et al: Endoscopic pituitary surgery: an early experience. Surg Neurol 1997;47:213–222;discussion 222– 223
REFERENCES
19. Klopp LS, Rao S: Endoscopic‐assisted intracranial tumor removal in dogs and cats: long‐term outcome of 39 cases. J Vet Intern Med 2009;23:108–115
1. Koblik PD, LeCouteur RA, Higgins RJ, et al: CT‐guided brain biopsy using a modified Pelorus Mark III stereotactic system: experience with 50 dogs. Vet Radiol Ultrasound 1999;40:434–440 2. Koblik PD, LeCouteur RA, Higgins RJ, et al: Modification and application of a Pelorus Mark III stereotactic system for CT‐ guided brain biopsy in 50 dogs. Vet Radiol Ultrasound 1999;40:424–433 3. Moissonnier P, Blot S, Devauchelle P, et al: Stereotactic CT‐ guided brain biopsy in the dog. J Small Anim Pract 2002;43: 115–123 4. Sawin P, Hichon PW, Follett KA, et al: Computed imaging‐ assisted stereotactic brain biopsy: a risk analysis of 225 consecutive cases. Surg Neurol 1998;49:640–649 5. Clar HE: Clinical and morphological studies of pituitary and diencephalic space‐occupying lesions before and after operation, with special reference to temperature regulation. Acta Neurochir 1979;50:153–199
20. Sanai N, Quinones‐Hinojosa A, Narvid J, et al: Safety and efficacy of the direct endonasal transsphenoidal approach for challenging sellar tumors. J Neurooncology 2008;87:317–325 21. Bhatki AM, Carrau RL, Snyderman JH, et al: Endonasal surgery of the ventral skull base—Endoscopic transcranial surgery. Oral Maxillofac Surg Clin North Am 2010;22:157–168 22. Cavallo LM, Prevedello DM, Solari D, et al: Extended endoscopic endonasal transsphenoidal approach for residual or recurrent craniopharyngiomas. J Neurosurg 2009;111:578–589 23. Gardner PA, Kassam AB, Rothfus WE, et al: Preoperative and intraoperative imaging for endoscopic endonasal approaches to the skull base. Otolaryngol Clin North Am 2008;41:215– 230 24. Gardner PA, Kassam AB, Snyderman CH, et al: Outcomes following endoscopic, expanded endonasal resection of suprasellar craniopharyngiomas: a case series. J Neurosurg 2008;109:6–16
6. Konovalov A: Microsurgery of tumors of diencephalic region. Neurosurg Rev 1983;6:37–41
25. Gardner PA, Kassam AB, Thomas A, et al: Endoscopic endonasal resection of anterior cranial base meningiomas. Neurosurgery 2008;63:36–52;discussion 52–54
7. Meij BP, Voorhout G, van der Ingh TS, et al: Results of transsphenoidal hypophysectomy in 52 dogs with pituitary‐ dependent hyperadrenocorticism. Vet Surg 1998;27:246–261
26. Chatzisotiriou A, Selviaridis P, Kontopoulos V: Delayed persistent hyperthermia after resection of a craniophayngioma. Pediatr Neurosurg 2004;40:196–202
8. Meij BP: Hypophysectomy as a treatment for canine and feline Cushing’s disease. Vet Clin North Am Small Anim Pract 2001;31:1015–1041
27. Kalapurakal JA, Silverman CA, Akhtar N, et al: Acute hyperthermia following stereotactic radiosurgery for pituitary adenoma. Br J Radiol 1999;72:1218–1221
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Hyperthermia After Transethmoidal CUSA‐Assisted Diencephalic Mass Removal
28. Laws ER, Jr.: Functional pituitary tumors. The neurosurgeon and neuroendocrinology. Clin Neurosurg 1980;27:3–18 29. Liu JK, Das K, Weiss MH, et al: The history and evolution of transsphenoidal surgery. J Neurosurg 2001;95:1083–1096 30. Meij BP, Auriemma E, Grinwis G, et al: Successful treatment of acromegaly in a diabetic cat with transsphenoidal hypophysectomy. J Feline Med Surg 2010;12:406–410 31. Meij BP, Mol JA, Bevers MM, et al: Residual pituitary function after transsphenoidal hypophysectomy in dogs with pituitary‐ dependent hyperadrenocorticism. J Endocrinol 1997;155:531– 539 32. Meij BP, Mol JA, Bevers MM, et al: Alterations in anterior pituitary function of dogs with pituitary‐dependent hyperadrenocorticism. J Endocrinol 1997;154:505–512 33. Meij BP, Mol JA, Hazewinkel HA, et al: Assessment of a combined anterior pituitary function test in beagle dogs: rapid sequential intravenous administration of four hypothalamic releasing hormones. Domest Anim Endocrinol 1996;13:161– 170
Marino et al.
40. Yoshikawa H, Oda Y, Sakajiri K, et al: Pure akinesia manifested neuroleptic malignant syndrome: a clinical variant of progressive supranuclear palsy. Acta Neuropathol (Berl) 1997;93:306–309 41. Carmel P: Surgical syndromes of the hypothalamus. Clin Neurosurg 1979;25:133–159 42. Branch E, Burger P, Brewer D: Hypothermia in a case of hypothalamic infarction and sarcoidosis. Arch Neurol 1971;25:245–255 43. Killefer F, Stern W: Chronic effects of hypothalamic injury. Arch Neurol 1970;22:419–429 44. Addy P, Hudson F: Diencephalic syndrome of infantile emaciation. Arch Dis Child 1972;47:339–343 45. Pelc S: The diencephalic syndrome in infants. Eur Neurol 1972;7:321–334 46. Davison C: Disturbances of temperature regulation in man, in The hypothalamus and central levels of autonomic regulation. New York, NY, 1940, pp 774–823 47. Ciric J, Zivin J: Neuroepithelial (colloid) cysts of the septum pellucidum. J Neurosurg 1975;43:69–73
34. Meij BP, Mol JA, van der Ingh TS, et al: Assessment of pituitary function after transsphenoidal hypophysectomy in beagle dogs. Domest Anim Endocrinol 1997;14:81–97
48. Little J, Carty CM: Colloid cysts of the third ventricle. J Neurosurg 1974;39:230–235
35. Kendrick M, Silverberg G: Transtemporal hypophysectomy in the dog. Surg Neurol 1975;4:244–246
49. Stein B, Frasier R, Tenner M: Tumors of the third ventricle. J Neurol Neurosurg 1972;35:776–788
36. Meij B, Voorhout G, Rijnberk A: Progress in transsphenoidal hypophysectomy for treatment of pituitary‐dependent hyperadrenocorticism in dogs and cats. Mol Cell Endocrinol 2002;197:89–96
50. Hanson JM, Teske E, Voorthout G, et al: Prognostic factors for outcome after transsphenoidal hypophysectomy in dogs with pituitary‐dependent hyperadrenocorticism. J Neurosurg 2007;107:830–840
37. Hanson JM, Voorhout G, Teske E, et al: Efficacy of transsphenoidal hypophysectomy in treatment of dogs with pituitary‐dependent hyperadrenocorticism. J Vet Intern Med 2005;19:687–694
51. Greco JJ, Aiken SA, Berg JM, et al: Evaluation of intracranial meningioma resection with a surgical aspirator in dogs: 17 cases (1996–2004). J Am Vet Med Assoc 2006;229:394–400
38. Lantz GC, Ihle SL, Nelson RW, et al: Transsphenoidal hypophysectomy in the clinically normal dog. Am J Vet Res 1988;49:1134–1142 39. Glass EN, Kapatkin A, Vite C, et al: A modified bilateral transfrontal sinus approach to the canine frontal lobe and olfactory bulb: surgical technique and five cases. J Am Anim Hosp Assoc 2000;36:43–50
894
52. Yamasaki T, Moritake K, Nagai H: A new miniature ultrasonic surgical aspirator with a handpiece designed for transsphenoidal surgery. J Neurosurg 2003;99:177–179 53. Luis E, Gutmann D: Meningioma. Curr Opin Neurol 2004;17:687–692 54. Bagley R, Harrington M, Gay J: Effects of changes in power setting of an ultrasonic aspirator on amount of damage to the cerebral cortex of healthy dogs. Am J Vet Res 2001;62:248–251
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