Masahiko Kawanishi

A novel robotic catheter system with force and visual feedback for vascular interventional surgery

This paper proposes a novel master-slave robotic catheter operating system with force feedback and visual feedback for vascular interventional surgery (VIS). The robotic catheter system has good manoeuvrability, it can transmit the surgeon’s skill to insert and rotate the catheter and avoids danger during VIS using force and visual feedback. In addition, it can be used to train unskilled surgeons to perform VIS. We performed a simulation experiment to validate our system using an endovascular evaluator (EVE). The experimental results demonstrated that the stability and response of the system were good. The robotic catheter system is suitable for performing VIS.

Effects of hypothermia on thrombin-induced brain edema formation

Recent studies have shown that thrombin plays an important role in brain edema formation after intracerebral hemorrhage (ICH). The possible mechanisms of thrombin-induced brain edema formation include blood-brain barrier (BBB) disruption and inflammatory response involving polymorphonuclear (PMN) leukocyte. Animal experiments have revealed that moderate therapeutic hypothermia improves pathological and functional outcome in various models of brain injury. In this study, we examined the effect of hypothermia on thrombin-induced brain edema formation. Effects of hypothermia on BBB permeability and the accumulation of PMN leukocytes were also determined to clarify the protective mechanism of hypothermia in this model. Anesthetized adult rats received an injection of 10 Units of thrombin into the basal ganglia. Animals were separated into the normothermic and hypothermic groups, which were housed in a room maintained at 25 degrees C and in a cold room maintained at 5 degrees C, respectively, for 24 h after the thrombin injection. The brain temperature in rats housed in a cold room reduced temporarily to approximately 30 degrees C and then gradually recovered to 35 degrees C by the end of the observation. Brain water content in the basal ganglia was significantly reduced in rats treated with hypothermia compared to the normothermic rats (84.3+/-0.2 vs. 82.4+/-0.1%; P<0.01). The decrease of brain water content was accompanied with a significant reduction in BBB permeability to Evans blue dye and in accumulation of PMN leukocytes. This study indicates that hypothermic treatment significantly reduces thrombin-induced brain edema formation in the rat. Inhibition of thrombin-induced BBB breakdown and inflammatory response by hypothermia appear to contribute to brain protection in this model. Hypothermic treatment may provide an approach to potentially reduce ongoing edema after ICH.

Detection of brain amyloid β deposition in patients with neuropsychological impairment after traumatic brain injury: PET evaluation using Pittsburgh Compound-B

Abstract Objective: Traumatic brain injury (TBI) is an epigenetic risk factor for Alzheimer’s disease (AD) and amyloid β (Aβ) deposition is observed histopathologically in the traumatized brain. This study was conducted to detect cerebral Aβ deposition using amyloid positron emission tomography (PET) in patients with neuropsychological impairment after TBI. Methods: Twelve patients with post-traumatic neuropsychological impairment (11 men and one woman, age range = 21–78 years) were examined using Pittsburgh Compound B (11C-PIB) PET at the chronic stage after TBI (range = 5–129 months). Results: 11C-PIB was positive in three patients and negative in the other nine patients. There was no correlation between 11C-PIB deposition and the severity of injury; initial CT findings; elapsed time from the injury; and neuropsychological test scores. Conclusions: The absence of Aβ deposition in many patients with chronic neuropsychological impairment after TBI does not support the premise that Aβ pathology progresses over time in the traumatized brain. Early and sequential 11C-PIB PET examination may clarify the time course of Aβ deposition in the traumatized brain and the relationship between traumatic brain insult and subsequent neuropsychological impairment.

Development of a Novel Robotic Catheter Manipulating System with Fuzzy PID Control

Manual operation of steerable catheter is inaccurate in minimally invasive surgery and requires dexterity for efficient manipulation of the catheter meanwhile exposes the surgeons to intense radiation. In this paper, our objective is to develop a remote control system that replaces the manipulation of surgeons with high accuracy. Increasing demands for flexibility and fast reactions in control method, fuzzy control can play an important role because the experience of experts can be combined in the fuzzy control rules to be implemented in the systems. We present a practical application of fuzzy PID controller for this developed system during the remote operations and compare with the traditional PID control experimentally. The feasibility and effectiveness of the control method are demonstrated. The performance using the fuzzy PID control is much better than using the conventional control method.

Treatment of cold injury-induced brain edema with a nonspecific matrix metalloproteinase inhibitor MMI270 in rats.

Blood-brain barrier (BBB) disruption is a critical event leading to vasogenic brain edema and secondary brain damage after cold injury-induced brain trauma. Matrix metalloproteinases (MMPs), a family of proteolytic enzymes which degrade the extracellular matrix, are implicated in BBB disruption in this model. The purpose of this study was to examine the effects of MMI270 (N-hydroxy-2(R)-[(4-methoxysulfony) (3-picolyl)-amino]-3-metylbutaneamide hydrochloride monohydrate), a synthetic nonspecific MMP inhibitor, on cold injury-induced brain edema in rats. Cold injury was induced by applying a copper probe cooled with liquid nitrogen on the parietal skull for 30 sec in 38 rats. Treatment with MMI270, a bolus injection at a dose of 30 mg/kg, was started immediately after the induction of cold injury and was continued for 24 h at a dose of 40 mg/kg/day using an intraperitoneal osmotic minipump (n = 7). In the untreated control group (n = 7), rats were administered a vehicle and implanted with a vehicle-containing osmotic pump. Two percent Evans Blue (EB) in saline (1 mL/kg) was administrated intravenously immediately after the cold injury in another group of rats, six of which were untreated and six of which were treated with MMI270 at the above dose. At 24 h after the cold injury, the brain water content and the BBB permeability to EB were determined. To assess the protective effect of MMI270 on secondary brain lesion after the cold injury, the MMI270-treated rats received a bolus injection at a dose of 30 mg/kg, followed by a continuous administration of MMI270 for 7 days at a dose of 40 mg/kg/day using an osmotic minipump (n = 6). In the untreated control group (n = 6), the rats were administered the vehicle and implanted with a vehicle-containing osmotic pump. At 7 days after cold injury, the secondary brain lesion was assessed using hematoxylin and eosin (H-E) staining. Compared with the untreated control group, treatment with MMI270 significantly reduced the brain water content in the ipsilateral core and intermediate areas (p < 0.05 and p < 0.01) and protected the BBB integrity to EB in the ipsilateral core area (p < 0.05) at 24 h after the cold injury. The secondary lesion was significantly smaller in the MMI270-treated animals compared with the untreated animals (p < 0.05) a 7 days after the cold injury. O kur results indicate that treatment with MMI270 in rats exhibits protection in acute brain edema formation and secondary brain damage by attenuating the BBB permeability after cold injury.

Association between YKL-40 and adult primary astrocytoma.

The YKL‐40 coding chitinase 3‐like 1 gene is 1 of the most overexpressed genes in human glioblastomas. The objectives of this study were to explore YKL‐40 protein expression status and World Health Organization (WHO) pathologic grades of primary human astrocytoma and to investigate the role of YKL‐40 in the proliferation of both established and primary astrocytoma cells in vitro.

Absence of orbito-ocular signs in dural carotid–cavernous sinus fistula with a prominent anterior venous drainage

A 55-year-old woman developed an intractable right orbitofrontal headache. The symptoms subsided spontaneously 2 months after onset, but diplopia due to right abducens nerve palsy had occurred, and gradually worsened. Orbito-ocular signs were never observed throughout the clinical course. Brain MRI and MR angiography demonstrated abnormal signal changes corresponding to the right cavernous sinus. Angiography confirmed a dural carotid-cavernous sinus fistula (CCF) with three directional drainage routes in the arterial phase. Although the most prominent draining vein was the superior ophthalmic vein (SOV), an outflow with a high flow rate into the angular facial vein prevented prolonged enhancement of the SOV in the venous phase. These findings suggest that the absence of orbito-ocular signs in dural CCF with an anterior venous drainage could be attributed to the relief of venous hypertension of the SOV.

Effects of Mild Hypothermia and Alkalizing Agents on Brain Injuries in Rats with Acute Subdural Hematomas

Brain ischemia is the leading pathopysiological mechanism in the development of secondary brain damage after acute subdural hematoma (SDH). Hypothermia has been employed as an effective cerebroprotective treatment on brain injuries, but the control of the general condition is very difficult under hypothermia, and various severe complications have been reported. Cerebral acidosis in the ischemic area is one of the important factors augmenting the brain edema formation. Tris-(hydroxymethyl)-aminomethane (THAM) has been used as an alkalizing agent for acidosis on brain injury and is reported to be effective. In the present study, we used a rat acute SDH model to assess the effect of mild (35 degrees C) hypothermia and THAM combined treatment on brain water content, brain ischemia, and blood-brain barrier (BBB) permeability at 4 h after hematoma induction. Mild hypothermia did not significantly reduce the brain water content beneath the hematoma (79.5 +/- 0.2%) compared to normothermia (80.2 +/- 0.2%), but mild hypothermia combined to THAM resulted in a significant reduction (78.7 +/- 0.0%; p < 0.01). Combined with mild hypothermia, THAM treatment significantly reduced the Evans blue extravasation (35 +/- 7 ng/g wet tissue; p < 0.05) compared to normothermia (63 +/- 7 ng/g wet tissue). Furthermore, the volume of infarction at 24 h after the hematoma induction (54 +/- 3 mm(3); p < 0.01) was significantly smaller by the combined treatment compared with normothermia (70 +/- 2 mm(3)). The present findings indicate that mild hypothermia of 35 degrees C combined with THAM presents a potent cerebroprotective strategy. The protection of the BBB is one of the possible cerebroprotective mechanisms in this rat acute SDH model.

The efficacy and safety of transvenous embolisation in the treatment of intracranial dural arteriovenuous fistulas

Abstract To evaluate the role of transvenous embolisation including its efficacy and safety in the treatment of intracranial dural arteriovenous fistulas (DAVFs), we retrospectively analysed seven cases of intracranial DAVFs treated with transvenous embolisation in combination with arterial embolisation. Four DAVFs were in the cavernous sinus, two in the transverse-sigmoid sinus, and one in the inferior petrosal sinus. The transarterial and transvenous embolic agents included fibred platinum coils (FPC) and int erlocking detachable coils (IDC). In all patients, the transaterial embolisation alone had failed to cure the DAVFs. After the combined transvenous embolisation, the anatomical cure was proven in five patients, and all patients were clinically cured. The re were no complications in any patient. In conclusion, the transvenous embolisation is a useful and safe approach in the management of intracranial DAVFs.

Impact of neurointensivist-managed intensive care unit implementation on patient outcomes after aneurysmal subarachnoid hemorrhage

PURPOSE The purpose of the study is to evaluate the impact of neurointensivist-managed intensive care unit (NIM-ICU) implementation for patients admitted with aneurysmal subarachnoid hemorrhage (SAH). METHODS This study retrospectively evaluated 234 patients (mean age, 61.7 years; male, 67) admitted with SAH between January 1, 2001, and March 31, 2014. Neurologic outcomes between patients admitted from January 2001 to December 2006 (intensivist-managed intensive care unit group) and January 2007 to March 2014 (NIM-ICU group) were compared. The primary outcome was the incidence of a good neurologic outcome at discharge (GO; the modified Ranking Scale score: GO, 0-2; poor neurological outcome, 3-6) at discharge. RESULTS Neurointensivist-managed intensive care unit was initiated for 151 (64.5%) of 234 patients. Univariate analysis demonstrated significantly better outcomes for NIM-ICU group vs intensivist-managed intensive care unit group (GOs, 58.3% vs 41.0%, respectively, P = .01). Multivariate logistic regression was used to evaluate NIM-ICU efficacy for SAH patients, but NIM-ICU was not significantly associated with GOs (P = .054). Subgroup analysis of patient grading by Hunt and Kosnik grades I to II showed that NIM-ICU implementation was an independent predictor of GOs (odds ratio, 4.54; 95% confidence interval, 1.08-22.17; P = .04). CONCLUSION Neurointensivist-managed intensive care unit may improve neurologic outcomes in SAH patients with Hunt and Kosnik grades I to II.