Search Results

You are looking at 1 - 10 of 15 items for

  • Author or Editor: Kazunori Arita x
  • Refine by Access: all x
Clear All Modify Search
Restricted access

Tetsuya Nagayama, Yosuke Nishimuta, Sei Sugata, Teruhiko Nishizawa, and Kazunori Arita

In patients with severe arteriosclerosis or anatomical variations such as a bovine arch, the insertion of a guiding catheter for carotid artery stenting is difficult. The authors use a guide wire system as an anchor and advance the guiding catheter to an area proximal to the stenotic structure. This method is useful and safer than others for carotid artery stenting.

Restricted access

Koji Iida, Kaoru Kurisu, Kazunori Arita, and Minako Ohtani

Object. The goal of this study was to elucidate the optimal time for rewarming of patients who have been treated with hypothermia for severe head injury.

Methods. Eleven patients with severe head injuries who had been treated by hypothermia underwent transcranial Doppler (TCD) ultrasonography examinations. The patients were divided into two groups: Group A consisted of three patients in whom acute brain swelling occurred during the rewarming period and Group B was composed of eight patients who displayed no significant intracranial hypertension during or after hypothermia therapy. In all patients, the mean flow velocity of the middle cerebral artery (FVMCA) recorded transcranially and the mean flow velocity of the internal carotid artery (FVICA), recorded high in the neck, were monitored at 24-hour intervals after the patient was admitted to the hospital. In Group A, the FVMCA was normal at 48 hours (maintenance state of hypothermia) in each patient, and abnormal increases and peak values (> 100 cm/second) occurred from 96 to 144 hours postinjury (rewarming period). The FVICA, which was monitored concurrently also varied as the FVMCA increased. The pulsatility indices in the arteries decreased at the time of the peak FVMCA. The enhanced FVMCA was consistent with hyperemia because of the low FVMCA/FVICA ratios (< 3). Two patients in whom jugular venous oxygen saturation was monitored were found to have high values (> 80%), representing hyperemia. All intracranial pressures (ICPs) that lay within the normal range at 48 hours postinjury elevated acutely after the peak FVMCA. In Group B, both FVMCA and FVICA values were normal at 48 hours postinjury and remained stable throughout the rewarming period. Values of ICP were also maintained within the normal range until the patients were weaned from hypothermia therapy.

Conclusions. Hyperemia, detectable by TCD ultrasonography, may serve as an index in the prediction of acute brain swelling, and rewarming should be terminated when such a hemodynamic phenomenon is observed.

Restricted access

Yasuyuki Kinoshita, Akira Taguchi, Atsushi Tominaga, Kazunori Arita, and Fumiyuki Yamasaki

OBJECTIVE

Recovery from adult growth hormone deficiency (AGHD) after transsphenoidal surgery (TSS) has not been well discussed because of the lack of examinations including pituitary provocation tests (PPTs) before and after the procedure. This study aimed to evaluate the growth hormone (GH) axis function of patients with nonfunctioning pituitary adenoma (NFPA) via pre- and postoperative PPTs. Moreover, the predictive factors for recovery from AGHD after TSS were validated to facilitate surgery for AGHD in patients with NFPA.

METHODS

In total, 276 patients (median age 60.0 years) who underwent TSS for NFPA were included in this study. PPTs were performed before and 3 months after TSS. Then, the relationships between recovery from AGHD after TSS and clinical, surgical, and hormonal factors, including peak GH level based on PPTs, were evaluated statistically.

RESULTS

In this study, 114 patients were diagnosed with preoperative AGHD. Approximately 25.4% recovered from AGHD after TSS. In contrast, among the 162 patients without preoperative AGHD, 13 (8.0%) had newly developed postoperative AGHD. The predictive factors for recovery from AGHD were younger age, female sex, initial TSS, and high peak GH level based on preoperative PPT. According to the receiver operating characteristic curve analysis, patients who were aged ≤ 62.2 years and had a peak GH level of ≥ 0.74 μg/L based on preoperative PPT were likely to recover from AGHD (sensitivity: 82.8%, specificity: 72.9%, and area under the curve: 0.8229).

CONCLUSIONS

AGHD caused by NFPA can improve after initial TSS among young patients with certain peak GH levels assessed by preoperative PPT. Whether TSS for NFPA can promote recovery from AGHD is worth considering in some patients.

Restricted access

Kazunori Arita, Kaoru Kurisu, Koji Iida, Ryosuke Hanaya, Tomohide Akimitsu, Seiichiro Hibino, Basant Pant, Masatake Hamasaki, and Shoji Shinagawa

✓ The authors report on a patient who exhibited intractable epilepsy due to an inaccessible hypothalamic hamartoma and subsequently underwent stereotactic radiosurgery. This 25-year-old man had a 24-year history of intractable gelastic and tonic—clonic seizures. Magnetic resonance (MR) imaging performed at examination as well as that performed 30 months earlier demonstrated a nonenhancing and nonprogressive spherical mass, approximately 10 mm in diameter, located on the patient's right side at the floor of the third ventricle. Focal radiation treatment performed with a gamma knife unit administered 36 Gy to the center and 18 Gy to the periphery of the lesion. This treatment resulted in an improvement in seizure control. Before the patient underwent radiosurgery, he suffered from three to six generalized seizures per month in spite of attentive compliance with an anticonvulsant medication regimen. After irradiation of the harmatoma, the frequency of the seizures transiently increased and then subsided 3 months posttreatment. The patient has been free of seizures for the last 21 months, with no neurological or endocrinological complications. Magnetic resonance imaging performed 12 months posttreatment demonstrated complete disappearance of the lesion.

Restricted access

Kazunori Arita, Atsushi Tominaga, Kazuhiko Sugiyama, Kuniki Eguchi, Koji Iida, Masayuki Sumida, Keisuke Migita, and Kaoru Kurisu

Object

The increase in the incidental detection of asymptomatic pituitary adenomas, known as “pituitary inciden-talomas,” led the authors to conduct a survey of the natural course of these lesions.

Methods

Forty-two patients with clinically nonfunctioning pituitary adenomas who had manifested no neurological or endocrinological disorders were monitored with magnetic resonance imaging studies. The follow-up period ranged from 10.8 to 168.2 months (mean ± standard deviation, 61.9 ± 38.2 months). The mean initial tumor size was 18.3 ± 7 mm.

In 21 patients, the tumor increased by at least 10% of its measured size on detection. This increase was first detected between 8.4 and 58.8 months (mean 31.8 ± 17.6 months) after diagnosis. There was no correlation between the original tumor size, patient age, or the presence of intratumoral cysts and tumor growth. Symptoms were noted in 10 patients during follow up; in four, extensive tumor necrosis accompanied hemorrhage, leading to severe headache, acute ophthalmological symptoms, and panhypopituitarism, which was indicative of pituitary apoplexy. Transsphenoidal surgery was performed in 12 patients with enlarged tumors, including three with apoplexy. With the exception of one apoplectic patient, visual function was recovered in all who underwent surgery. All apoplectic patients continue to manifest hypopituitarism.

Conclusions

In the course of 4 years, the size of the incidentalomas increased in 40% of 42 patients and became symptomatic in 20%. During the 5-year follow up, pituitary apoplexy developed in 9.5%. These findings may justify early intervention, especially in young individuals with incidentally found macroadenoma.

Restricted access

Kazunori Arita, Kaoru Kurisu, Atsushi Tominaga, Fusao Ikawa, Koji Iida, Selji Hama, and Haruyuki Watanabe

✓ A size-adjustable plate constructed of pure titanium is proposed for use in the reconstruction of the sella turcica. The plate is composed of two semicircular pieces that are connected by a hinge located at the top of the plate. Using an applicator, the plate is inserted into the sella turcica in a closed position. The same applicator is then used to open and secure the plate. The titanium causes minimal ferromagnetic artifacts on postoperative magnetic resonance imaging.

Preliminary findings indicate a possibie clinical use for this plate in the reconstruction of the sella turcica when no suitable piece of bone is available.

Restricted access

Yasuyuki Kinoshita, Akira Taguchi, Fumiyuki Yamasaki, Atsushi Tominaga, Kazunori Arita, and Nobutaka Horie

OBJECTIVE

Rathke’s cleft cysts (RCCs) are relatively common and often detected incidentally. They are usually asymptomatic and managed conservatively. However, little is known about their natural history. Thus, the authors aimed to examine the natural course of RCCs and identify the risk factors for their progression.

METHODS

This retrospective study examined 229 patients (median age 43.0 years) diagnosed with RCCs by MRI and followed up without surgery (median period 36.6 months). The median cyst height on the initial MRI was 10 mm. Progression or regression of RCC was defined as cyst height changes of ≥ 1 mm.

RESULTS

In total, 23 (10.0%) RCCs progressed, whereas 73 (31.9%) RCCs spontaneously regressed. The remaining 133 were noted to be stable throughout the follow-up period. Patients with progressed RCCs were significantly older than those with stable RCCs. In patients with acute headache as an initial symptom, RCCs were significantly more likely to spontaneously regress. New symptoms occurred in 6 patients, 5 of whom underwent surgery for RCC progression. Of these 6 patients, 1 patient had persistent adrenocorticotropic hormone deficiency and 1 patient developed diabetes insipidus. Kaplan-Meier analysis results showed RCC progression and new symptom development rates to be 12.0% and 4.1% at 5 years and 13.7% and 5.7% at 10 years, respectively.

CONCLUSIONS

RCCs rarely progress or cause new symptoms in the long term. Patients with asymptomatic RCC should be followed up for at least 5 years to ensure RCC inactivity. RCCs in older adults may require greater surveillance.

Full access

Yasuyuki Kinoshita, Atsushi Tominaga, Satoshi Usui, Kazunori Arita, Tetsuhiko Sakoguchi, Kazuhiko Sugiyama, and Kaoru Kurisu

OBJECTIVE

Patients with symptomatic Rathke's cleft cysts (RCCs) managed by surgical treatment often experience recurrence. The authors attempted to clarify the outcome of surgically treated RCCs over a long-term follow-up period.

METHODS

Ninety-one consecutive RCC patients with a follow-up period of more than 12 months (mean 80.2 months, range 12–297 months) were retrospectively studied. The authors examined the clinical features and postoperative course of patients who experienced a reaccumulation of cyst contents visible on MRI after the initial surgery, and they investigated data from the patients who underwent reoperation for symptomatic recurrent RCCs.

RESULTS

Reaccumulation of cyst contents occurred in 36 patients (39.6%). In 34 of these patients, a reaccumulation occurred in the first 5 years after surgery. The initial cysts in these patients were most often large, with squamous metaplasia in the cyst walls. Thirteen patients (14.3%) with recurrent symptoms underwent a reoperation, and 10 of the 13 patients had a reaccumulation of RCCs within the 1st year after surgery. The reoperations were performed in the 1st year (61.5%) or several years later (23.1%). Patients were likely to initially have had a visual disturbance and the cyst walls likely included squamous metaplasia. However, no association was observed between the incidence of reaccumulation/reoperation of RCCs and the surgical procedure for RCCs.

CONCLUSIONS

The reaccumulation rate of RCC is high in the long-term period, and it is associated with the histological findings but not with the surgical procedure. Long-term monitoring, for a period of at least 5 years, should therefore be conducted to identify and assess any RCC reaccumulation.

Restricted access

Kazunori Arita, Kaoru Kurisu, Atushi Tominaga, Kazuhiko Sugiyama, Fusao Ikawa, Hiroyuki Yoshioka, Masayuki Sumida, Yukari Kanou, Koji Yajin, and Ryusuke Ogawa

✓ The authors treated two patients with pituitary apoplexy in whom magnetic resonance (MR) images were obtained before and after the episode. Two days after the apoplectic episodes, MR imaging demonstrated marked thickening of the mucosa of the sphenoid sinus that was absent in the previous studies. The relevance of this change in the sphenoid sinus was investigated.

Retrospective evaluations were performed using MR images obtained in 14 consecutive patients with classic pituitary apoplexy characterized by acute onset of severe headache. The mucosa of the sphenoid sinus had thickened predominantly in the compartment just beneath the sella turcica, in nine of 11 patients, as ascertained on MR images obtained within 7 days after the onset of apoplectic symptoms. This condition improved spontaneously in all four patients who did not undergo transsphenoidal surgery. The sphenoid sinus mucosa appeared to be normal on MR images obtained from three patients at the chronic stage (> 3 months after onset). The incidence of sphenoid sinus mucosal thickening during the acute stage was significantly higher in the patients with apoplexy than that in the 100 patients without apoplexy. A histological study conducted in four patients who underwent transsphenoidal surgery during the early stage showed that the subepithelial layer of the sphenoid sinus mucous membrane was obviously swollen.

The sphenoid sinus mucosa thickens during the acute stage of pituitary apoplexy. This thickening neither indicates infectious sinusitis nor rules out the choice of the transsphenoidal route for surgery.

Restricted access

Satoshi Yamaguchi, Tetsuya Nagayama, Kuniki Eguchi, Masaaki Takeda, Kazunori Arita, and Kaoru Kurisu

Object

The purpose of this study was to evaluate the accuracy of multidetector-row CT angiography (MDCTA) in demonstrating spinal dural arteriovenous fistulas (SDAVFs).

Methods

The authors studied 10 patients with SDAVFs, including 2 with spinal epidural AVFs, who underwent preoperative MR imaging, MDCTA, and digital subtraction angiography (DSA). In the evaluation of coronal sections of multiplanar reformation MDCTA images, inspection was focused on the presence of the following findings: 1) dilated perimedullary veins in the spinal canal; 2) focal enhancement of the nerve root, suggesting the location of the AVF, around the dural sleeve; and 3) a radicular vein that drains the AVF into perimedullary veins. The utility of MDCTA was assessed by comparing its findings with those of DSA in each case.

Results

Digital subtraction angiography confirmed that the AVFs were located in the thoracic spine in 4 patients and in the lumbar spine in 6 patients, and MDCTA detected dilated perimedullary veins in all 10 patients. In 8 patients, there was focal enhancement of the nerve root. The radicular vein that drains the AVF into the perimedullary veins was found in 8 cases. In 8 cases, the MDCTA-derived level and side of the AVF and its feeder corresponded with those shown by DSA. In 2 patients, however, the MDCTA-derived side of the feeder was on the side contralateral to the feeding artery confirmed by DSA. These lesions were interpreted as spinal epidural AVFs with perimedullary drainage. In 2 cases, MDCTA could not detect the multiplicity of their feeders.

Conclusions

The use of MDCTA preceding DSA can be helpful to focus the selective catheter angiography on certain spinal levels. However, one should keep in mind that epidural AVFs with perimedullary drainage may resemble SDAVFs and also that MDCTA cannot exclude the possibility of multiple feeders. Further research should elucidate how broadly selective angiography should explore around the MDCTA-suggested target.