Abstract: BACKGROUND: The aim of this study is to report our use of new bioabsorbable screws in cervical anterior fusion. These screws need not be removed because they are completely absorbed by resolution in vivo. We describe our method and the new bioabsorbable screws. METHODS: We used PLLA screws until September 2004 and uncalcined uHA-PLLA screws thereafter. They are completely absorbed by resolution to water and carbon dioxide upon in vivo hydrolysis. The uHA-PLLA screws are x-ray impenetrable, and their uHA content renders them osteoconductive. In cervical anterior fusion, the graft is inserted in the area of deletion resulting from decompression. The screws are inserted in the 4 corners of the vertebral body and graft. In long fusion, they are introduced in the 2 lateral wings of the bone graft on each vertebral body and in the 4 corners. Our method eliminates the need for plates or mesh. RESULTS: We have used this method in 62 patients and encountered no complications. There were no screw or graft extrusions and no surgery-related infections. The patients were able to walk a few hours after the operation and wore a simple neck collar for a few days. CONCLUSIONS: This safe and easy method shortens the hospital stay and reduces the risk of graft extrusion and complications associated with the use of nonabsorbable devices.
Abstract: BACKGROUND: The transvertebral approach is useful for decompression in patients with cervical radiculopathy; because the intervertebral disk is preserved, moveability is retained. We performed wide deletion of the vertebral body to increase the patient population eligible for treatment with this approach and include patients with compression of the cervical spinal cord. METHODS: In patients undergoing anterior decompression, we performed vertebrotomy (13 x 8 mm) at the midline of the cervical vertebral body at the upper level using a surgical saw. The resulting hole facilitates decompression of the cervical cord and nerve root; a ceramic insert is introduced in the area of deletion. To prevent graft extrusion, the bilateral wings of the bone graft are fastened with bioabsorbable screws. RESULTS: We used this approach in 163 patients with several cervical diseases. Collapse of the vertebral body and fusion of the operated intervertebral disk were encountered in only 1 patient (0.61%). There was no significant difference between pre- and postoperative alignment. Reoperation was required in 7 patients whose symptoms did not improve, in 1 with disk hernia, in 5 with severe spondylosis, and in 1 with combined-type OPLL. CONCLUSIONS: Although this approach is appropriate in patients undergoing cervical anterior decompression, the narrowness of the visual field may result in insufficient decompression, and its indication is restricted to patients with cervical disk hernia, mild cervical spondylosis, and segmental OPLL. In patients with segmental instability, continuous or combined OPLL, severe cervical spondylosis, and kyphosis, this approach should not be used.
Abstract: Far-out syndrome (FOS) is a rare disease in which the L5 nerve root is compressed by a transverse process, the sacral ala, and a bony spur at the extraforaminal zone. We report the case of patient with FOS due to a bulging disc and review the literature. This 34-year-old male experienced severe left leg pain and slight motor weakness of the left extensor digitorum. Radiographic studies revealed no abnormality in the spinal canal. The intervertebral disk bulged to the left. Because of fat it was difficult to discern the left L5 nerve root from the sacral ala in the extraforaminal zone. His symptoms failed to respond to conservative treatment and he underwent decompression of the L5 nerve root without fusion. During the operation, the left L5 nerve root was exposed by drilling the sacral ala via the left paraspinal approach. The sacral ala was removed along with the left L5 nerve root to obtain sufficient pulsation and movement of the left L5 nerve root. Neither the intervertebral joint nor the intervertebral disk was removed. The patient's symptoms disappeared immediately after surgery. Due to anatomical factors, the L5 nerve root is easily compressed and the presence of this syndrome should be considered in a differential diagnosis. Careful and appropriate decompression without fusion yielded an excellent outcome.
Abstract: OBJECTIVE: We report our experience with the SONOPET ultrasonic bone curette. METHODS: Between September 2001 and July 2005, 546 patients underwent microscopic spinal surgeries using a high-speed drill and the SONOPET instrument. RESULTS: We encountered operative complications thought to be attributable to the use of the SONOPET in six patients (1.1%). There were five instances of dural puncture and one spinal cord injury. All dural tears occurred when the dura mater was aspirated into the tip of the SONOPET. None of the affected patients developed postoperative clinical complications because cerebrospinal fluid leakage was avoided by appropriate closure. We think that the transient spinal cord injury occurred because the vibration emanating from the SONOPET was transmitted directly to the spinal cord. Some patients experienced damage to the epidural venous plexus for reasons similar to those described above. CONCLUSION: SONOPET facilitates the removal of bone in a narrow field, such as that encountered during keyhole surgery. It aids in the removal of the lateral edge of bone and is especially useful for expanding the foramen intervertebrale or opening the lateral recess. However, its use is not without risk. To prevent dural tears and venous plexus injury, we recommend that cotton be placed between the SONOPET and important structures. To avoid spinal cord injury, we suggest that the SONOPET be inserted horizontal with the dura mater to avoid the direct transmission of vibrations emanating from the instrument to the spinal cord. SONOPET is suitable for decompression on the lateral side, but not for decompression above the spinal cord.
Abstract: We describe a giant aneurysm of the anterior communicating artery (ACoA) which was treated with a STA-RA graft-A3 bonnet bypass and A3-A3 side-to-side anastomosis. A giant and partially thrombosed ACoA aneurysm was partially coated 3 years before his current presentation, its gradual increase producing visual field disturbances. An A3-A3 side-to-side anastomosis and STA-RA graft-A3 bonnet bypass were performed. The aneurysm was dissected, and the thrombus removed under transient parent-artery occlusion. The aneurysmal neck was successfully clipped without encountering ischemic changes. This strategy may be useful for treating giant or thrombosed aneurysms in the region of the ACoA.
Abstract: Hypoxia-inducible factor (HIF)-1alpha is a transcription factor in hypoxia adaptation mechanisms. In malignant tumors, HIF-1alpha upregulates vascular endothelial growth factor (VEGF) expression to induce tumor angiogenesis. Although VEGF and HIF-1alpha are expressed in pituitary adenomas, the relationships of these factors remain unclear. Therefore, we examined the expression of HIF-1alpha and VEGF using real-time RT-PCR and immunohistochemistry to clarify the relationship of these factors in pituitary adenomas. HIF-1alpha mRNA and VEGF mRNA levels in pituitary adenoma tissues from 25 operated patients were quantified using real-time RT-PCR. Some tissues were also studied by double fluorescent immunohistochemical methods. HIF-1alpha mRNA and protein were expressed in all pituitary adenomas examined. Their expression tended to be higher in GH-producing and lower in ACTH-producing tumors. VEGF mRNA and protein were also expressed in all pituitary adenomas. There was no significant correlation in the expression levels of HIF-1alpha and VEGF mRNA. The mutual expression of HIF-1alpha and VEGF was of no significance; in only a few cells were HIF-1alpha and VEGF co-localized. Our results suggest that in pituitary adenomas VEGF expression may not depend strongly on HIF-1alpha expression.
Abstract: BACKGROUND: Measurement of dural sinus or drainage vein pressure is useful for determining the appropriate treatment for some patients. We report a novel measurement procedure that reduces bleeding from the needle puncture site as well as further tearing of the wall. METHODS: The vessel is punctured through the patch by gelatin sponge with fibrin sealant and a siliconized elastic needle is introduced. After obtaining the desired measurements, the needle is withdrawn through the fibrin sealant-bearing patch whose presence facilitates sealing of the puncture site. To further decrease the incidence of complications due to incomplete hemostasis, an additional identically prepared path is placed over the site. RESULTS: We have used this method in several operations and have encountered no complications. Our method also makes it possible to safely approach the drainers of pial arteriovenous malformations. CONCLUSIONS: Our method is easy and convenient and prevents the leakage of blood from the puncture site and further tearing of the venous wall.
Abstract: Unilateral spondylolysis and midline defects in the posterior spinal elements attributable to spina bifida occulta (SBO) result in the unilateral floating of the vertebral arch. We report a patient with unilateral spondylolysis associated with SBO in the lumbar spine and review the literature. This 71-year-old male experienced severe left leg pain and lumbago that worsened upon walking. Radiographic studies revealed SBO and unilateral spondylolysis of L5. The dural sac and left L5 nerve root were compressed by the organization of tissues around the spondylolysis. As his symptoms failed to respond to conservative treatment, he underwent unilateral laminectomy without fusion. At operation, the left lamina of L5 was floating and unstable; the right lamina was stable. Medial facetectomy at L4/5 and excision of the left floating lamina of L5 were performed. For satisfactory decompression of the dural sac and left L5 nerve root, the cartilaginous fibrous tissue around the lysis was removed. His symptoms disappeared immediately after surgery. Although long-term follow-up is necessary, we suggest that unilateral microdecompression without fusion is a useful method to treat patients with unilateral spondylolysis with SBO.
Abstract: We document the co-localization of honeycomb golgi and ACTH-immunopositive granules in giant ACTH-producing pituitary adenoma cells. A 42-yr-old woman presented with Cushing's disease and a giant adenoma that invaded the sphenoid and cavernous sinus. She underwent transsphenoidal surgery followed by radiation therapy. Some of the adenoma cells were ACTH-positive and upon electron-microscopic (EM) study most were found to contain sparse granules and no type-I filaments. In many cells the golgi complex had undergone partial or total vacuolar transformation that resulted in the appearance of honeycomb golgi. Immunohistochemical study of mirror sections of portions containing cells with honeycomb golgi revealed that the cells with honeycomb golgi showed ACTH-immunopositivity. Honeycomb golgi, which was formerly considered a morphological marker of gonadotroph adenomas in females, has previously been identified in large ACTH-producing pituitary adenomas but there has been no direct evidence that individual cells with honeycomb golgi are cells that produce ACTH. Our immunohistochemical documentation of ACTH-immunoreactivity in individual adenoma cells containing honeycomb golgi clearly confirms that honeycomb golgi is not confined only to gonadotroph adenomas in females. Rather, the existence of honeycomb golgi in cells of other adenoma types may be due to their low hormone production and/or to disturbances in the regulation of the exocytotic pathway.
Abstract: OBJECTIVE: Double pituitary adenomas are extremely rare. They can be divided into contiguous and clearly separated types. Most contiguous tumours are surgically removed as one tumour and the co-existence of different adenoma types can be confirmed by histological methods. In contrast, detailed preoperative neuroimaging studies can suggest the co-existence of separated multiple adenomas. In patients with multiple adenomas, surgical failure may result when one adenoma is missed during surgery. Among 600 surgical cases we encountered four patients with clearly separated double pituitary adenomas; all were highly suspect on preoperative MRI studies. PATIENTS AND RESULTS: All four patients manifested acromegalic symptoms; one patient also exhibited hyperprolactinemia and two had familial pituitary adenomas unrelated to multiple endocrine neoplasia type I (MEN-1). All underwent transsphenoidal surgery and histology confirmed the diagnosis of GH-producing plus gonadotroph adenoma in two cases and of two GH-producing adenomas each in the other two patients. CONCLUSION: Although the pathogenesis of our double adenomas remains unknown, genetic abnormalities may be involved because two patients had familial pituitary adenomas unrelated to MEN-1. When preoperative MRI is suggestive of double adenomas, careful surgical exploration is necessary to avoid missing the other adenoma because the risk of surgical failure is high, especially in patients with functioning adenomas.
Abstract: OBJECTIVE: Ghrelin and its receptor, growth hormone secretagogue (GHS) receptor (GHSR), are expressed in the normal pituitary gland and various types of pituitary adenoma. Somatic mutations in the subunit of Gs alpha protein (gsp), which led to a constitutive activation of adenylyl cyclase, are reported in GH-producing pituitary adenomas. We analysed the relationship between ghrelin mRNA and GHSR mRNA expression levels in gsp mutation-positive and -negative GH-producing pituitary adenomas. PATIENTS: Pituitary adenoma tissue was obtained at surgery from 20 patients with acromegaly. METHODS: The expression levels of human ghrelin mRNA and GHSR mRNA were quantified using a competitive RT-PCR method. To detect the gsp mutations, amplified Gs alpha subunit cDNA fragments were sequenced directly using RT-PCR method. RESULTS: There was no significant difference in the expression of ghrelin mRNA between mutation-positive and -negative adenomas. The expression of GHSR mRNA was significantly lower in gsp mutation-positive than -negative adenomas. There was a significant negative correlation between the levels of ghrelin mRNA and GHSR mRNA expression in mutation-negative adenomas; no such correlation was found in mutation-positive adenomas. CONCLUSION: These results suggest that GHSR mRNA expression is downregulated by ghrelin in gsp mutation-negative GH-producing pituitary adenomas, and that changes in intracellular signalling pathways in gsp mutation-positive GH-producing pituitary adenomas affect the expression of G protein-coupled receptors such as GHSR. The absence of negative correlation between ghrelin and GHSR expression might be induced by lowered GHSR expression in gsp mutation-positive GH-producing adenomas.
Abstract: OBJECTIVE: Thyrotrophin-releasing hormone (TRH) paradoxically induces the release of growth hormone (GH) when injected intravenously into acromegalic patients, although the mechanism of this action is unknown at present. Several research groups have reported that the level of TRH receptor-1 (TRHR-1) mRNA expression is variable in pituitary adenomas, and does not correlate with the degree of paradoxical GH response to TRH administration in a limited number of acromegalic patients. We aimed to compare the expression levels of TRHR-1 mRNA among various types of pituitary adenoma and to clarify whether these levels correlate with the degree of pituitary hormone response to TRH. PATIENTS: Pituitary adenoma tissue was obtained by surgery from 14 patients with acromegaly, four with prolactinomas, nine with nonfunctioning adenomas and one with a TSH-producing adenoma. METHODS: The level of human TRHR-1 mRNA expression in each adenoma was quantified using the competitive reverse transcription polymerase chain reaction (RT-PCR) METHOD: For amplification of a TRHR-1 cDNA fragment, a sense primer was designed according to the sequence in exon 2 and an antisense primer designed according to the sequence located at the region in exon 3 that does not encode for the alternative splicing-generated short form of TRHR-1 mRNA. RESULTS: TRHR-1 mRNA was detected in all pituitary adenomas examined and did not correlate with their size. The mean level of TRHR-1 mRNA expression was significantly lower in GH-producing adenomas than in prolactinomas and nonfunctioning adenomas (1.4 +/- 0.4 x 10(-2) attomol/microg total RNA, 10.7 3.4 x 10(-2) attomol/microg total RNA, and 7.2 +/- 3.3 x 10(-2) attomol/g total RNA, respectively). The ratio of plasma peak GH induced by TRH administration to the basal level of plasma GH in the patients with acromegaly correlated positively with the level of TRHR-1 mRNA expression in their GH-producing adenomas (r = 0.620, P = 0.0179). The responsiveness of plasma PRL and gonadotrophin to TRH in the patients with prolactinoma and nonfunctioning pituitary adenoma did not significantly correlate with the levels of TRHR-1 mRNA expression in their pituitary adenomas, respectively. CONCLUSIONS: The findings of the present study suggest that the level of TRHR-1 mRNA expression varies among different types of pituitary adenoma. Furthermore, in acromegaly, the responsiveness of plasma GH to TRH administration appears to at least partially depend on the level of TRHR-1 mRNA expression in the GH-producing pituitary adenoma.
Abstract: OBJECTIVE: The level of growth hormone (GH), growth hormone secretogogue (GHS) and GHS receptor (GHSR) messenger ribonucleic acid (mRNA) expression has been reported as being higher in GH-producing pituitary adenomas than in other types of pituitary adenomas. Recently, ghrelin, an endogenous ligand specific for GHSR, was isolated. Therefore, we attempted to clarify whether ghrelin mRNA is expressed in various types of human pituitary adenoma by competitive reverse transcription-polymerase chain reaction (RT-PCR). We also examined the relationship between the levels of ghrelin or GHSR mRNA and hormonal and tumour characteristics in patients with pituitary adenomas. PATIENTS: Pituitary adenoma tissue was obtained at surgery from 13 patients with acromegaly, 4 with prolactinomas, 5 with gonadotrophin (Gn)-producing adenomas, 4 with non-functioning adenomas, 2 with ACTH-producing adenomas and 2 with TSH-producing adenomas. METHODS: The expression levels of human ghrelin mRNA and GHSR mRNA were quantified using a competitive RT-PCR method. RESULTS: Ghrelin mRNA was detected in all pituitary adenoma tissues examined, with the highest mean level detected in non-functioning adenomas, a moderate level in GH-producing adenomas and Gn-producing adenomas, and the lowest level in prolactinomas. The level of ghrelin mRNA expression in GH-producing adenomas correlated negatively with the size of the adenoma (n = 13) (r = - 0.756, P = 0.0028). Furthermore, the mean level of ghrelin mRNA expression in high-grade (III and IV of Hardy classification) GH-producing adenomas was significantly lower than that in low-grade (I and II) GH-producing adenomas (P = 0.0016). GHSR mRNA was also detected in all pituitary adenomas with the highest mean level in GH-producing adenomas, a moderate level in nonfunctioning adenoma, and the lowest level in prolactinoma and Gn-producing adenomas. CONCLUSIONS: Ghrelin mRNA, in addition to GHSR mRNA, is expressed in various types of pituitary adenoma with different levels of expression in each type. Our findings suggest that ghrelin produced in pituitary adenoma may play some role in the mechanism underlying the development of adenoma cells through autocrine and/or paracrine pathways.
Abstract: OBJECTIVE AND IMPORTANCE: We describe a very rare case involving a ruptured intracranial aneurysm at the distal posteroinferior cerebellar artery (PICA) branching from the extracranial vertebral artery. CLINICAL PRESENTATION: A 53-year-old woman experienced the sudden onset of a severe occipital headache and vomiting. Computed tomographic scanning revealed subarachnoid and intraventricular hemorrhage. Cerebral angiography of the left vertebral artery demonstrated the left PICA branching from the extracranial segment of the extracranial vertebral artery at the level of C2; a saccular aneurysm arose from the intracranial portion of the distal PICA. INTERVENTION: Via the transcondylar approach, we were able to obtain adequate visualization without retracting important structures. To avoid injury to the anomalous PICA, the aneurysm was clipped. CONCLUSION: Only four other cases of a distal aneurysm of the PICA branching from the extracranial vertebral artery have been reported in the literature. In all cases, the aneurysm originated at the intradural extracranial portion of the PICA. To our knowledge, the case presented here is the first report of a ruptured aneurysm at the level of the intracranial portion of the PICA branching from the extracranial segment of the vertebral artery.
Abstract: A case is presented of fenestration of the vertebral artery in a 36-year-old woman who had various neurological symptoms with Basedow's disease. We also review 7 cases from the literature. Our patient had had occipital neuralgia and numbness of the left side of the neck and left upper limb several weeks before admission. On admission she had hyperthyroidism. MRI, left vertebral angiography, and 3D-CT scans demonstrated a fenestrated vertebral artery compressing the upper cervical cord. The patient's symptoms gradually improved as her thyroid function was controlled. A possible explanation is that the fenestrated vertebral artery might have compressed the neural structures, resulting in her various symptoms. Occipital neuralgia was apparently caused by the fenestrated artery compressing the C1 and C2 sensory roots. A fenestrated vertebral artery is usually of no clinical significance. The reason for the late onset of symptoms in the present case is unknown, but it may have been due to hemodynamic stress caused by her hyperthyroidism. After her thyroid function was controlled, the hemodynamic stress presumably decreased and the symptoms resolved spontaneously.
