Training in endoscopic endonasal transsphenoidal surgery using a skull model and eggs.

BACKGROUND: Recently, endoscopic pituitary surgery is increasingly being used in pituitary surgery. Compared to conventional microscopic pituitary surgery, outcomes have been non-inferior, so endoscopic pituitary surgery has become an established surgical technique. However, this is a highly specialized surgery and sophisticated surgical techniques are required. We report our development of a training model for endoscopic endonasal transsphenoidal surgery. METHODS: Our training model is constructed using a skull model and eggs. The sella turcica of the skull model is hollowed out and an egg is placed. The bottom of the egg simulates the sella turcica floor and the egg contents simulate a tumor. Training is conducted using this model in an actual operating room with actual surgical instruments. RESULTS: This model is highly realistic and is within acceptable limits as a surgical simulation. Since practice can be repeated, this model is effective for familiarization with endoscopic imaging and to increase technical skills such as drilling and curetting. In addition, variations in eggs, ranging from raw eggs to boiled eggs, can be used to simulate various tumors for training. CONCLUSIONS: This training model using a skull model and eggs is useful to improve surgical techniques in endoscopic endonasal transsphenoidal surgery.

Upregulation of water channel aquaporin-4 in experimental autoimmune encephalomyeritis.

Aquaporin-4 (AQP4) is a water channel protein that plays an important role in water movement in the central nervous system (CNS). Recently, presence of anti-AQP4 antibody has been reported in the sera from patients with neuromyelitis optica. AQP4 is therefore a possible target for inflammatory mechanisms in CNS. In the present investigation, we performed semi-quantitative analysis of AQP4-mRNA in brain and spinal cord from mice affected with experimental autoimmune encephalomyelitis (EAE) using real-time PCR. AQP4-mRNA expression was increased in EAE; reaching a peak in the spinal cord at 14 days, and in the brain at 21 days after first inoculation. Immunohistochemical analysis showed that AQP4 is expressed on astrocytes, indicating that the increase in AQP4 expression may correlate with astrocytic activation. This is the first study to demonstrate upregulation of AQP4 in EAE. The upregulation of AQP4 could be involved in the development of inflammation in the acute phase of EAE.

[Treatment of leptomeningeal carcinomatosis from gastric cancer].

Leptomeningeal carcinomatosis is a serious complication leading to a fatal outcome in patients with gastric cancer. We tried to treat leptomeningeal carcinomatosis from gastric cancer with intrathecal chemotherapy using methotrexate (MTX)and cytosine arabinoside(Ara-C). We described and discussed the therapeutic strategy. Six patients with leptomeningeal carcinomatosis from gastric cancer were admitted in our institution from March 2004 to July 2007. Three of 6 patients were accepted for intrathecal chemotherapy. They received intraventricular injections of MTX(5 mg)and Ara-C(20 mg)through the Ommaya reservoir. The other 3 patients who rejected the therapy were conservatively treated with betamethasone, carbamazepine and glyceol. Two of the intrathecal chemotherapy group received whole-brain radiotherapy after the initial intrathecal chemotherapy. The mean survival time was 122.3 days(median survival time 35.0 days). The survival of the intrathecal chemotherapy group was from 39 to 367 days, whereas the survival of the conservative treatment group was from 10 to 31 days. The intrathecal chemotherapy improved not only survival but also clinical symptoms dramatically. Intrathecal chemotherapy is thus recommended for leptomeningeal carcinomatosis from gastric cancer.

Intradural spinal arachnoid cyst contributing to sudden paraparesis.

BACKGROUND: Spinal arachnoid cysts are cystic lesions filled with cerebrospinal fluid that contributes to neurological deficits depending on their size/location within the spinal canal. Here, we report a patient with a spinal subarachnoid cyst who suddenly developed paraparesis. CASE DESCRIPTION: A 37-year-old female with a thoracic spinal arachnoid cyst at the T7 level suddenly developed lower abdominal pain followed by immediate paraparesis. Two weeks following the onset of symptoms, she underwent a T6-T8 laminectomy; this included with full cyst excision. By the 4th postoperative week, her signs/symptoms fully resolved. CONCLUSIONS: A 37-year-old female with a T7 thoracic spinal subarachnoid cyst who presented with acute paraparesis regained normal function 2 weeks following a T6-T8 laminectomy.

A case of lymphomatoid granulomatosis followed for 14 months on the basis of clinical and histological findings.

Lymphomatoid granulomatosis (LYG) is a systemic granulomatous disease characterized by B-cell proliferation of uncertain malignant potential. It most frequently affects the lungs but also occasionally affects the central nervous system. Its pathophysiology is unclear in numerous respects, thus making it difficult to diagnose and treat. We recently encountered a case of LYG that was followed clinically and histologically for 14 months. A 55-year-old man was hospitalized with multiple brain tumors for which the final diagnosis was not made until the second surgery, 14 months after the first intervention. Following the diagnosis, he was treated with steroid pulse therapy. At present, 3.5 years after the onset of LYG, the patient is in good condition with no signs of tumor recurrence. Although LYG is usually graded on the basis of histological findings, this patient showed no histological changes or any increase in disease grade during the 14-month follow-up period.

[Effectiveness of intraoperative fluorescence for diagnosis of malignant lymphoma].

Primary central nervous system lymphoma is generally treated with radiochemotherapy, but surgical treatment can be used in combination with biopsy. We used fluorescein Na to provide intraoperative fluorescence during biopsy to improve the safety and accuracy of surgical treatment. After dural incision, fluorescein Na was administered intravenously at 20 mg/kg, which is double the usual dose, and appeared in the tumor after 10 to 15 minutes. Yellow-stained tissue was collected during stereotactic biopsy. Strongly fluorescent tumor cells were observed under the microscope; these cells would have otherwise been difficult to distinguish from normal brain tissue. Sufficient fluorescence was observed endoscopically, and we conclude that use of fluorescein Na is effective in diagnosis and surgery for malignant lymphoma.

Regrowth and progression of multiple calcifying pseudoneoplasms of the neuraxis: Case report.

BACKGROUND: Calcifying pseudoneoplasms of the neuraxis (CAPNONs) are clinically rare, nonneoplastic, noninflammatory-calcified lesions of the central nervous system. Resection of a lesion usually indicates good prognosis without recurrence. However, we experienced a unique case of CAPNON that repeatedly recurred after resection. CASE DESCRIPTION: A 52-year-old woman with recurrence of an undiagnosed brain tumor, which was resected 12 years ago, was admitted to our institution. Three calcifying lesions along with perifocal edema were detected in the frontal interhemispheric fissure. We performed the second surgery for total removal of the lesions. The patient was diagnosed with CAPNON on the basis of the clinical features of the lesions and medical examination results. However, 14 months after the second surgery, recurrence occurred, and the patient has been followed up conservatively thereafter. CONCLUSION: CAPNONs may indicate healing process associated with an unidentified agent. Maximum resection, including an unidentified agent, is necessary to prevent recurrence.

Usefulness of contralateral carotid angiography in revascularization therapy of acute internal carotid artery occlusion.

OBJECTIVE The vascular lumen of an acutely occluded internal carotid artery (ICA) generally contains numerous thrombi. Therefore, carotid angiography on the affected side during revascularization therapy of acute ICA occlusion has a potential risk of causing distal embolization. In this study the authors propose the use of contralateral carotid angiography. METHODS Six patients with acute ICA occlusion underwent revascularization therapy using a stent retriever or Penumbra system. Revascularization therapy was performed with placement of a 9-Fr balloon-guiding catheter (BGC) in the affected ICA and a 4-Fr diagnostic catheter in the contralateral ICA. During the procedure, the 9-Fr BGC was kept inflated, and all control angiography was performed from the 4-Fr diagnostic catheter. After thrombectomy, contralateral carotid angiography combined with manual aspiration from the 9-Fr BGC was performed to assess the presence or absence of residual thrombi in the affected ICA. The 9-Fr BGC was deflated only after the complete absence of residual thrombi in the affected ICA was confirmed. RESULTS The time required for introducing the 4-Fr diagnostic catheter into the contralateral ICA was within a few minutes in all patients. Residual thrombi in the affected ICA were found in 3 of 6 patients. The residual thrombi in these 3 patients were completely removed; thus, distal embolization was prevented. CONCLUSIONS Contralateral carotid angiography is useful for avoiding distal embolization during revascularization therapy of acute ICA occlusion. Further studies involving a larger number of patients are warranted to verify the clinical efficacy of this contralateral carotid angiography.

Transfemoral Stenting of Stenoses at the Common Carotid Artery Origin Using an Anchoring Technique With a Balloon Protection Device.

BACKGROUND: Transfemoral stenting of stenoses at the common carotid artery (CCA) origin is technically difficult because of poor stability of the guiding catheter. OBJECTIVE: To describe an anchoring technique using a balloon protection device that provides excellent stability of the guiding catheter. METHODS: Four patients (5 stenotic lesions) with stenosis of the CCA origin underwent transfemoral stenting with a balloon protection device (PercuSurge GuardWire; Medtronic, Santa Rosa, California). These 5 stenotic lesions of the CCA origin included 1 on the right side and 4 on the left side. Two of the stenoses were symptomatic, and 3 were asymptomatic. A balloon-expandable stent (Express LD stent; Boston Scientific, Natick, Massachusetts) was used in all patients. RESULTS: All stenoses were successfully dilated. With the balloon protection device as an anchor in all patients, the guiding catheter was highly stable during the procedure. There were no intraprocedural or periprocedural ischemic complications in any patients. None of the patients developed a stroke during a mean follow-up period of 8.4 months. CONCLUSION: The anchoring technique using a balloon protection device is useful for transfemoral stenting of stenoses at the CCA origin. ABBREVIATIONS: CCA, common carotid arteryECA, external carotid arteryICA, internal carotid arteryPTA, percutaneous transluminal angioplasty.

Role of N-methyl-D-aspartate receptors and the nitric oxide pathway in nociception/hyperalgesia elicited by protease-activated receptor-2 activation in mice and rats.

Activation of the peripheral protease-activated receptor-2 (PAR-2) triggers nociceptive behaviour and thermal hyperalgesia in rats. The present study created a novel mouse model for PAR-2-triggered nociception, and then examined the roles of NMDA receptors and the nitric oxide (NO) pathway in nociceptive processing by PAR-2. Intraplantar administration of the PAR-2 agonist SLIGRL-NH(2) elicited nociceptive responses in mice, an effect being more specific in mast cell-depleted mice. This PAR-2-triggered nociception was abolished by the NMDA receptor antagonist MK-801, but not the neuronal NO synthase inhibitor 7-nitro indazole. In contrast, the PAR-2-triggered thermal hyperalgesia in rats was blocked by both agents. Our study thus provides a novel mouse model for PAR-2-mediated nociception, and suggests that NMDA receptors are involved in PAR-2-triggered nociception and hyperalgesia, while NO contributes only to the latter.

Fluorescence-guided surgery of metastatic brain tumors using fluorescein sodium.

We aimed to demonstrate the effectiveness of fluorescence-guided surgery of metastatic brain tumors using fluorescein sodium. The study comprised 38 patients with metastatic brain tumors who underwent tumor resection after intravenous injection of fluorescein sodium. The local recurrence rate was investigated in 36 of the 38 patients, and compared for patients who had undergone surgery only and surgery plus whole-brain radiotherapy (WBRT). In 31 of 36 patients, the tumors had been completely resected using fluorescence-guided surgery. Postoperative WBRT was not performed in 20 of the 31 patients who underwent gross total resection. Although the recurrence rate for these 20 patients was 20%, compared to 9.1% for the 11 patients who also underwent postoperative WBRT, the difference was not statistically significant. Use of fluorescein sodium in metastatic brain tumor surgery may reduce the rate of local recurrence, and thus help improve the quality of life for these patients.

Surgical technique for a cystic-type metastatic brain tumor: transformation to a solid-type tumor using hydrofiber dressing.

BACKGROUND: Many metastatic brain tumors have a distinct border with normal brain tissue, which facilitates tumor removal. However, residual tumor tissue may be present after surgery when metastatic brain tumors are of cystic type. We have developed a method using hydrofiber dressing to transform cystic-type into solid-type tumors. METHODS: Hydrofiber dressing is a sodium carboxymethylcellulose hydrocolloid polymer with high fluid-absorptive capacity. This material was originally used as a dressing for exudative wounds. Hydrofiber dressing was used for 8 patients with cystic-type metastatic brain tumor. Tumor removal was performed after hydrofiber dressing was inserted into the cyst cavity to transform the tumor into a solid-type tumor. RESULTS: Transformation of cystic-type metastatic brain tumors into smaller solid-type tumors using hydrofiber dressing facilitated en bloc resection of tumor. The dressing also absorbed residual cyst fluid and was thus also effective in preventing intraoperative dissemination of tumor cells. This approach enabled ideal en bloc resection in all patients. There were no adverse events. CONCLUSIONS: These findings suggest hydrofiber dressing may be useful in surgery for cystic-type metastatic brain tumors.

The regulation of liver regeneration by the plasmin/alpha 2-antiplasmin system.

BACKGROUND/AIMS: The regeneration after liver injury is regulated by the release and activation of several growth factors. The role of the plasmin/alpha(2)-antiplasmin (alpha(2)-AP) system in liver regeneration was investigated. METHODS: CCl(4) was injected intraperitoneally into the mice deficient (-/-) in fibrinolytic factors: alpha(2)-AP-/-, plasminogen (Plg) -/-, and Plg-/-.alpha(2)-AP-/-, and wild-type (WT) mice. The liver tissue was examined for its microscopic appearance, fibrinolytic activity, and fibronectin levels. RESULTS: In the gene deficient and WT mice, the livers exhibited the same extent of necrosis 2 days after the CCl(4) injection. The livers of the WT mice normalized after 7 days, and the alpha(2)-AP-/- mice normalized after 5 days. In contrast, the livers of the Plg-/- and Plg-/-.alpha(2)-AP-/- mice remained in the damaged state until 14 days after the liver injury. The injection of anti-alpha(2)-AP antibody in the WT mice improved the regeneration after the liver injury, and the injection of tranexamic acid in the alpha(2)-AP-/- mice reduced. CONCLUSIONS: These results suggest that the plasmin/alpha(2)-AP system played an important role in hepatic repair via clearance from the injury area.

Modulation of capsaicin-evoked visceral pain and referred hyperalgesia by protease-activated receptors 1 and 2.

Protease-activated receptors (PARs) 1 and 2 are expressed in capsaicin-sensitive sensory neurons, being anti- and pro-nociceptive, respectively. Given the possible cross talk between PAR-2 and capsaicin receptors, we investigated if PAR-2 activation could facilitate capsaicin-evoked visceral pain and referred hyperalgesia in the mouse and also examined the effect of PAR-1 activation in this model. Intracolonic (i.col.) administration of capsaicin triggered visceral pain-related nociceptive behavior, followed by referred hyperalgesia. The capsaicin-evoked visceral nociception was suppressed by intraperitoneal (i.p.) TFLLR-NH2, a PAR-1-activating peptide, but not FTLLR-NH2, a control peptide, and unaffected by i.col. TFLLR-NH2. SLIGRL-NH2, a PAR-2-activating peptide, but not LRGILS-NH2, a control peptide, administered i.col., facilitated the capsaicin-evoked visceral nociception 6-18 h after administration, while i.p. SLIGRL-NH2 had no effect. The capsaicin-evoked referred hyperalgesia was augmented by i.col. SLIGRL-NH2, but not LRGILS-NH2, 6-18 h after administration, and unaffected by i.p. SLIGRL-NH2, and i.p. or i.col. TFLLR-NH2. Our data suggest that PAR-1 is antinociceptive in processing of visceral pain, whereas PAR-2 expressed in the colonic luminal surface, upon activation, produces delayed sensitization of capsaicin receptors, resulting in facilitation of visceral pain and referred hyperalgesia.