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Biomedical subjects

J Inamasu

Publications and source records attributed to J Inamasu.

At least 19 recordsLinked to original sources

Vascular injury and complication in neurosurgical spine surgery.

Vascular injury is an uncommon, but not rare complication of spine surgery. The consequence of vascular injury may be quite devastating, but its incidence can be reduced by understanding the mechanisms of injury. Properly managing vascular injury can reduce mortality and morbidity of patients. A review of the literature was conducted to provide an update on the etiology and management of vascular injury and complication in neurosurgical spine surgery. The vascular injuries were categorized according to each surgical procedure responsible for the injury, i.e., anterior screw fixation of the odontoid fracture, anterior cervical spine surgery, posterior C1-2 arthrodesis, posterior cervical spine surgery, anterolateral approach for thoracolumbar spine fracture, posterior thoracic spine surgery, scoliosis surgery, anterior lumbar interbody fusion (ALIF), lumbar disc arthroplasty, lumbar discectomy, and posterior lumbar spine surgery. The incidence, mechanisms of injury, and reparative measures were discussed for each surgical procedure. Detailed coverage was especially given to vascular injury associated with ALIF, which may have been underestimated. The accumulation of anatomical knowledge and advanced imaging studies has made complex spine surgery safer and more reliable. It is not clear, however, whether the incidence of vascular injury has been reduced significantly in all procedures of spine surgery. Emerging new techniques, such as microendoscopic discectomy and lumbar disc arthroplasty, seem to be promising, but we need to keep in mind their safety issues, including vascular injury and complication.

Blood Vessels↗

Three-dimensional computed tomographic anatomy of the abdominal great vessels pertinent to L4-L5 anterior lumbar interbody fusion.

A recent accumulation of surgical and radiological literature has helped spine surgeons to better understand the anatomy and establish surgical trajectories to the anterior L4-L5 disc space. However, the preoperative display of anatomic data in individual subjects in the three-dimensional (3-D) mode has rarely been attempted. The objective of this study was to acquire 3-D images of the abdominal great vessels pertinent to the L4-L5 anterior lumbar interbody fusion (ALIF), and to better define the radiological vascular anatomy. The 3-D images of 100 subjects with non-spinal diseases, generated from abdominal computed tomography angiography (CTA), were analyzed retrospectively. The anatomy of the great vessels pertinent to the L4-L5 ALIF procedure was investigated by measuring the level of the abdominal aorta (AA) bifurcation and that of the inferior vena cava (IVC) confluence in relation to the lumbar vertebral body. These two complexes were segmented into upper or lower parts, or disc level. The visibility of the middle sacral artery (MSA) and the left L4 lumbar artery on the 3-D images was also assessed. The AA bifurcation level was above L4 in 4, at L4 in 55, at L4-L5 in 23, and at L5 in 18 subjects. The IVC confluence level was at L4 in 17, at L4-L5 in 14, at L5 in 68 and below L5 in 1 subject. Levels of the bifurcation of the AA/IVC as combined data showed that the AA bifurcation was usually located 1 - 2 segments above the IVC confluence. The MSA and L4 segmental artery were identified in 79 and 83 subjects, respectively. The 3-D images of the abdominal great vessels together with the lumbar spinal column were reliably depicted. Anatomic data obtained from this study are in accordance with those obtained from conventional 2-D studies, and the 3-D images can serve as a versatile tool for preoperative evaluation for the ALIF candidates and can contribute to the reduction of surgical time and perioperative vascular complications.

Abdomen↗

Laparoscopic anterior lumbar interbody fusion: a review of outcome studies.

Laparoscopic anterior lumbar interbody fusion (LALIF) was first reported in 1995. It was expected to reduce the morbidity of an open ALIF, while maintaining its advantages. About a decade after its debut, the feasibility and short-term efficacy of the LALIF has been recognized. Currently, other minimally-invasive surgical options have been made available for the treatment of lumbar degenerative disc disease, and thus the role of LALIF has not been established in view of these other methods. The authors aim to clarify this, by conducting a review of the literature particularly on the outcome studies of LALIF. Several comparative studies showed that at the L5-S1 disc level, there was no marked difference between LALIF and the open or mini-open ALIF in terms of short-term efficacy, i. e., operative time, blood loss, and length of hospital stay. With regard to the complication rate, however, there was a higher incidence of retrograde ejaculation in LALIF. At the L4-L5 and L4-L5/L5-S1 disc levels, the complication rate and conversion rate to open surgery was high in LALIF, and many authors were not impressed with the LALIF at these levels. Several case series showed that the LALIF yielded excellent perioperative outcomes in the hands of experienced endoscopic spine surgeons at both the L5-S1 and L4-L5 disc levels. No conclusion regarding either the superiority or inferiority of LALIF to the open or mini-open ALIF can be drawn, because of the lack of data with a high-level of evidence. It cannot be denied, however, that some spine surgeons are abandoning this procedure and switching to the mini-open ALIF. Treatment of lumbar degenerative disc disease itself has been changing rapidly, as represented by the recent emergence of the lumbar artificial disc, and the future role of LALIF remains to be followed closely.

Evidence-Based Medicine↗

Iatrogenic vertebral artery injury.

Iatrogenic vertebral artery injury (VAI) results from various diagnostic and therapeutic procedures. The objective of this article is to provide an update on the mechanism of injury and management of this potentially devastating complication. A literature search was conducted using PubMed. The iatrogenic VAIs were categorized according to each diagnostic or therapeutic procedure responsible for the injury, i.e., central venous catheterization, cervical spine surgery, chiropractic manipulation, diagnostic cerebral angiography, percutaneous nerve block, and radiation therapy. The incidence, mechanisms of injury, and reparative procedures were discussed for each type of procedure. The type of VAI depends largely on the type of procedure. Laceration was the dominant type of acute injury in central venous catheterization and cervical spine surgery. Arteriovenous fistulae and pseudoaneurysms were the delayed complications. Arterial dissection was the dominant injury type in chiropractic manipulation and diagnostic cerebral angiography. Inadvertent arterial injection caused seizures or stroke in percutaneous nerve block. Radiation therapy was responsible for endothelial injury which in turn resulted in delayed stenosis and occlusion of the vertebral artery (VA). The proximal VA was the most vulnerable portion of the artery. Although iatrogenic VAIs are rare, they may actually be more prevalent than had previously been thought. Diagnosis of iatrogenic VAI may not always be easy because of its rarity and deep location, and a high level of suspicion is necessary for its early detection. A precise knowledge of the surgical anatomy of the VA is essential prior to each procedure to prevent its iatrogenic injury.

Aneurysm, False↗

Endoscopic ventriculo-cystomy for non-communicating hydrocephalus secondary to quadrigeminal cistern arachnoid cyst.

INTRODUCTION: Intracranial arachnoid cysts are developmental, anomalous collections of cerebrospinal fluid (CSF), and occasionally cause symptoms when large enough to obliterate the CSF outflow pathway and give rise to non-communicating hydrocephalus. The treatment of choice for symptomatic arachnoid cysts has been surgical excision or fenestration of the cyst, but less invasive endoscopic fenestration has been attempted with favorable preliminary results. CASE REPORT: We report a case of non-communicating hydrocephalus caused by a quadrigeminal cistern arachnoid cyst in a 35-year-old woman who presented with worsening headaches. She was successfully treated by endoscopic third ventriculostomy and fenestration of the cyst (ventriculo-cistomy). DISCUSSION: Endoscopic fenestration of symptomatic arachnoid cysts can be as effective as open surgery in terms of short-term efficacy, and it is certainly less invasive than open surgery. However, its long-term outcome remains unknown, and these rare cases require careful clinical and radiological follow-up.

Adult↗

Survival of a subarachnoid hemorrhage patient who presented with prehospital cardiopulmonary arrest: case report and review of the literature.

A 63-year-old woman was admitted to the intensive care unit after resuscitation from prehospital cardiopulmonary arrest (CPA). A brain CT scan revealed a subarachnoid hemorrhage (SAH), which was considered to be the cause of the CPA. The patient recovered neurologically after admission, and the elevated intracranial pressure (ICP) was controlled by inducing mild hypothermia. The day after admission, cerebral angiography revealed a ruptured cerebral aneurysm. The aneurysm was successfully treated with detachable coils by an endovascular technique. Mild hypothermia was continued for 3 days, and the patient was gradually rewarmed. After rehabilitation, the patient was discharged to her home with severe disability. Although aneurysmal SAH is one of the most common causes of CPA, survival of SAH patients after CPA is rare. This case illustrates the ability and possibility of multidisciplinary treatment, including the use of endovascular techniques and mild hypothermia, to improve the outcome of SAH patients with CPA who have been considered to be inoperable and untreatable.

Cardiopulmonary Resuscitation↗

Selective paralysis of the upper extremities after odontoid fracture: acute central cord syndrome or cruciate paralysis?

A patient presented with selective paralysis of the arms after having sustained a fall. X-ray of the cervical spine showed a type II odontoid fracture with posterior atlantoaxial dislocation. The diagnosis in the emergency room was cruciate paralysis, which is frequently associated with fractures of axis and/or atlas. However, magnetic resonance imaging (MRI) of the cervical spine revealed a lesion consistent with the acute central cord syndrome (CCS) at the C2-C6 level. The patient underwent posterior atlantoaxial arthrodesis to correct instability and was discharged, without much neurological improvement. Cruciate paralysis has been reported to be associated with fractures of axis and/or atlas, and acute CCS has rarely been associated with the fractures. However, this case illustrates that the lesion responsible for selective paralysis of the upper extremities is not as specific as it had been thought to be, and that it is difficult to accurately identify the level of the cervical cord injury by neurological diagnosis and X-rays alone. Supplementary diagnostic modalities, particularly MRI, are required to make a correct diagnosis and develop a therapeutic strategy.

Acute Disease↗

Intra-ischemic hypothermia attenuates intercellular adhesion molecule-1 (ICAM-1) and migration of neutrophil.

Adhesion of neutrophil to the endothelium and subsequent transmigration has been reported to contribute to progression of focal ischemia. Hypothermia has been known to attenuate ischemic insult through various mechanisms of action. The authors evaluated the effect of hypothermia on expression of intercellular adhesion molecule-1 (ICAM-1) protein and on transmigration of neutrophil with immunohistochemical method. Transient focal ischemia model in rats was employed, and animals received 2 h of either normothermic or hypothermic ischemia. To confirm the effectiveness of hypothermia on neuroprotection, cortical infarct area was compared between the two groups. Our results demonstrated that hypothermia reduced both the number of microvessels expressing ICAM-1 and that of neutrophils migrating into ischemic tissue. Comparison of cortical infarct area showed persistent protective effect. This study indicates that reduction of ICAM-1 expression and subsequent reduction of migrating neutrophil in hypothermia can contribute to attenuation of ischemic damage.

Animals↗

Cerebral microaneurysms found incidentally during aneurysm surgery.

Not uncommonly, cerebral microaneurysms are found incidentally during surgery for another previously diagnosed cerebral aneurysm(s). The frequency and angiographic characteristics of such incidental microaneurysms are retrospectively summarized. Seventeen patients were identified as harboring incidental microaneurysms, comprising 4.9% of the whole series. The middle cerebral artery (MCA) was the most frequent location (seven cases, 41%) of these microaneurysms. There was a tendency for MCA microaneurysms to be contiguous to a previously known, larger aneurysm at the same location. Neurosurgeons as well as interventional neuroradiologists should be aware of the possible presence of these incidental microaneurysms while treating patients with a cerebral aneurysm(s). Although the actual clinical implications of these incidental microaneurysms have not been elucidated, the few additional risks to patients already surgically exposed for the treatment of another aneurysm, along with the possible benefit of preventing their rupture and growth, would justify the surgical treatment of these microaneurysms.

Adult↗

Post-ischemic hypothermia delayed neutrophil accumulation and microglial activation following transient focal ischemia in rats.

Following ischemia, inflammation has been demonstrated to be involved in the progression of the tissue damage. Intra-ischemic hypothermia has been shown to attenuate the adverse activities of neutrophils and microglia. We investigated whether neutrophil accumulation and/or microglial activation is attenuated in post-ischemic hypothermia following transient focal ischemia in rats. After 1 h of ischemia, the neutrophil accumulation and the microglial activation was evaluated immunohistochemically. Percent infarct area was compared at 1, 2, 3, 5, and 7 days after ischemia/reperfusion. In hypothermia, the neutrophil accumulation was delayed but not attenuated. In normothermia, the accumulation reached the peak at 2 days after ischemia. The peak shifted to 3 days in hypothermia. Similarly, the microglial activation was delayed in hypothermia. Comparison of the infarct area showed significant protection by hypothermia at 1 and 2 days after reperfusion. However, hypothermia failed to show significant protection after 3 days and later. These results show that the delayed neutrophil accumulation and the microglial activation can be responsible for the loss of persistent protection in post-ischemic hypothermia.

Animals↗

Postischemic hypothermia attenuates apoptotic cell death in transient focal ischemia in rats.

Hypothermia confers potent neuroprotection against ischemic injury. Attenuation of apoptosis by hypothermia can be one of the responsible mechanisms. In this study, in situ DNA nick-end labeling (TUNEL) and immunostaining of Bax protein were performed to evaluate the effect of postischemic hypothermia on apoptotic cell death, employing rodent transient focal ischemia. Animals received 1 hour of transient focal ischemia. Brain temperature was maintained at 37.5 +/- 0.5 degrees C during ischemia. Immediately after reperfusion, animals were assigned to either a normothermic or hypothermic group. In hypothermia, animals were cooled and brain temperature was lowered to 34.5 +/- 1.0 degrees C. Prolonged hypothermia was maintained for 16 hours and animals rewarmed. In both groups, TUNEL and immunostaining of Bax was performed. In normothermia, the number of TUNEL positive cells reached the peak at 2 days after ischemia and decreased gradually. In hypothermia, the peak was shifted to 3 days after ischemia. The number of TUNEL positive cells in hypothermia was persistently below that of normothermia. Similarly, in hypothermia, immunostaining of Bax showed attenuated immunoreactivity compared with that in normothermia. In conclusion, postischemic hypothermia reduced both the number of TUNEL positive cells and immunoreactivity of Bax, which may be one of the responsible mechanisms with which hypothermia exerts neuroprotection.

Animals↗

Long-term outcome of 17 cases of large-giant posterior fossa aneurysm.

Long-term outcome of 17 patients who harbored a large or giant aneurysm of posterior fossa was summarized. The anatomical distribution of aneurysms included eight cases of basilar artery (BA) bifurcation aneurysms, three cases of BA trunk aneurysms, and six cases of vertebral artery (VA) aneurysms. Eight patients received surgical or endovascular treatment for their lesion. The clinical outcome was good recovery in six, moderate disability in one, and vegetative state in one case, respectively. The other nine patients were followed conservatively. Four of them had fatal aneurysmal rupture, and another two patients suffered from aggravation of pre-existing symptoms related to their aneurysm. Only three patients remain intact. Comparison of the radiographic parameters between those who bled and those who did not bleed revealed that those with subsequent rupture had significantly higher rate of aneurysmal thrombus and had a trend for larger diameter of the aneurysm. Although more aggressive and multidisciplinary measure should be taken to these patients to improve their long-term outcome, our results showed the limitation of treatment for these patients in the present era at the same time. The patients with broad neck BA bifurcation aneurysm in which efferent vessels were incorporated into aneurysmal dome, and those with fusiform, giant BA trunk aneurysm with thrombus were the least amenable to treatment in our series.

Adult↗

Basilar artery occlusion due to mucormycotic emboli, preceded by acute hydrocephalus.

A rare case of brain stem infarction caused by mucormycotic emboli, preceded by acute hydrocephalus, is reported. The patient, who had suffered from leukemia and had undergone bone marrow transplantation several months before, presented initially with seizure and persistent disturbance of consciousness. A head CT scan revealed marked ventricular dilation and diagnosed as acute hydrocephalus. The patient received emergent ventricular drainage. Despite the aggressive treatment, the patient did not survive. Autopsy revealed systemic mucormycosis occluding and invading various arteries including basilar artery and its branches, causing fatal brainstem infarction. Although early diagnosis remains difficult in the cases of systemic mucormycosis, prompt initiation of treatment is mandatory; one must have in mind the possibility of presence of fungal infection when treating patients with acute neurological deterioration who have underlying debilitating diseases, even though fungi themselves are hard to detect in most cases.

Acute Disease↗