Mechanical Properties of a 3 Dimensional-Printed Transparent Flexible Resin Used for Vascular Model Simulation Compared with Those of Porcine Arteries.

PURPOSE: To develop a vascular intervention simulation model that replicates the characteristics of a human patient and to compare the mechanical properties of a 3-dimensional (3D)-printed transparent flexible resin with those of porcine arteries using the elastic modulus (E) and kinetic friction coefficient (µk). MATERIALS AND METHODS: Resin plates were created from a transparent flexible resin using a 3D printer. Porcine artery plates were prepared by excising the aorta. E values and the adhesive strengths of the resin and arterial surfaces toward a polyethylene plate, were measured with a tensile-compressive mechanical tester. Resin transparency was measured using an ultraviolet-visible light spectrometer. The µk value of the resin plate surface after applying silicone spray for 1-5 seconds and that of the artery were measured using a translational friction tester. RESULTS: E values differed significantly between the arteries and resin plates at each curing time (0.20 MPa ± 0.04 vs 8.53 MPa ± 2.37 for a curing time of 1 minute; P < .05). The resin was stiffer than the arteries, regardless of the curing times. The visible light transmittance and adhesive strength of the resin decreased as the curing time increased. The adhesive strength of the artery was the lowest. The µk value of the silicone-coated resin surface created by applying silicone for 2-3 seconds (thickness of the silicone layer, 1.6-2.0 µm) was comparable with that of the artery, indicating that the coating imparted a similar slippage to the resin as to the living artery. CONCLUSIONS: A transparent flexible resin is useful for creating a transparent and slippery vascular model for vascular intervention simulation.

The impact of atherosclerotic factors on cerebral aneurysm is location dependent: aneurysms in stroke patients and healthy controls.

Previous studies have indicated that cerebrovascular diseases (CVDs) seem to increase the occurrence of unruptured intracranial aneurysms (UIAs). However, this maybe explained by the fact that CVDs and UIAs share common risk factors, such as hypertension (HT) and smoking. To clarify the impact of atherosclerotic risk factors on cerebral aneurysmal formation, we explored the incidence of UIAs and their locations in healthy controls and patients with CVD, who frequently have atherosclerotic risk factors. This study included consecutive 283 asymptomatic healthy adults and 173 acute stroke patients, from patients diagnosed with acute cerebral hemorrhage or cerebral infarction and admitted to our hospital. The incidence, maximum diameter, and location of UIAs were evaluated, and we also investigated the following factors: age, gender, current smoking, HT, diabetes mellitus (DM), and dyslipidemia. UIAs were found in 19 of the total 456 subjects (4.2%), 11 of 283 healthy subjects (3.9%), and 8 of 173 stroke patients (4.6%). These differences are not statically significant. The incidence of middle cerebral artery (MCA) aneurysms was significantly higher in the CVD patients than in the healthy controls (P = .03), and the incidence of paraclinoid aneurysms was significantly higher in the healthy controls than in the CVD patients (P = .03). Moreover, higher incidences of HTs and CVDs in the MCA aneurysms than in the other locations of UIAs were observed. These results indicate that the impact of atherosclerotic factors on cerebral aneurysmal formation depends on their location and that there is a stronger impact on MCA aneurysms than on paraclinoid aneurysms.

Usefulness of preoperative simulation with patient-specific hollow vascular models for high-flow renal arteriovenous fistula embolization using a preloading coil-in-plug technique.

The development of three-dimensional printers has facilitated the creation of patient-specific hollow vessel models. Preoperative simulations using these types of models have improved our ability to select appropriate devices and embolic materials before performing complex endovascular procedures. This report describes 2 cases of high-flow renal arteriovenous fistulas (r-AVFs) that were successfully treated via short-segment embolization using the preloading coil-in-plug (p-CIP) technique. To our knowledge, this is the first report of r-AVF being treated using the p-CIP technique. Our findings demonstrate that preoperative simulation has the potential to improve the safety and reliability of complex vascular embolization procedures.

[Lumbar canal stenosis with overactive bladder presenting urinary incontinence developed by walking: a case report].

A 74-year-old male complained of lower back pain, paresthesia of the bilateral feet and urinary incontinence. Urinary incontinence manifested at rest and worsened with walking. He had a history of surgery for prostatic cancer. Lumbar magnetic resonance imaging (MRI) demonstrated lumbar canal stenosis at the L4/5 level. The investigations including a cystometrogram manifested an overactive bladder caused by lumbar canal stenosis. His clinical symptoms were unresponsive to conservative treatment and posterior decompression at the L4/5 level was performed surgically to treat lumbar canal stenosis. Postoperatively, his symptoms were relieved. Overactive bladder presenting urinary incontinence that deteriorates with walking due to lumbar canal stenosis is suspected of being caused by circulatory disturbance of the cauda equine or conus medullaris. Emergency treatment including surgery is required for urinary retention in patients with lumbar canal stenosis; however, some degree of urinary disturbance may persist even after prompt and adequate surgery. Overactive bladder such as the present case should be considered as a possible symptom of lumbar canal stenosis, and surgical treatment for lumbar canal stenosis may be considered in the 'overactive bladder' stage before urinary retention begins, if the patient does not respond to conservative treatment.

[Sacroiliac joint dysfunction with groin pain after an operation for lumbar spinal disorder. A case report].

A 75-year-old male presented with groin pain after an operation to treat lumbar spondylolisthesis (L5). Groin tenderness was localized to the medial border of the anterior superior iliac spine (ASIS). Radiographical and physical examination raised the suspicion of sacroiliac joint (SIJ) dysfunction. Injection of a painkiller into the SIJ relieved symptoms, including groin tenderness. Symptoms improved gradually, and finally disappeared after five SIJ injections. Groin pain has been reported as a referred symptom of SIJ dysfunction in 9.3-23% of patients. Prior to the patient undergoing surgery to treat lumbar spondylolisthesis, SIJ dysfunction had not been noted on physical examination. Long periods spent in the abnormal posture due to lumbar spondylolisthesis induced SIJ stress. After the operation, an improvement in daily activity actually increased stress on the SIJ, resulting in SIJ dysfunction. Certain pathologies, including SIJ dysfunction, should be considered as residual symptoms after operations for lumbar spinal diseases.

Rare Case of Spinal Dural Arteriovenous Fistula with Radiculopathy, without Myelopathy or Spinal Edema on Magnetic Resonance Imaging.

BACKGROUND: Spinal dural arteriovenous fistulas (SDAVFs) are the most common type of spinal arteriovenous malformations; they frequently cause progressive myelopathy including gait disturbances and sensory disorders. CASE DESCRIPTION: We report a rare case of a middle-aged man who experienced right-sided chest pain and Th4 radiculopathy, without any other neurologic presentations. Magnetic resonance imaging showed a flow void sign on the dorsal aspect of the spinal cord; spinal angiography revealed an arteriovenous shunt between a radicular artery and an intradural vein. Suspecting SDAVF as the cause of the chest pain, we performed surgical resection. Intraoperatively, we observed compression of the rootlet by the draining vein. Right chest pain disappeared completely after obliteration of the SDAVF. The present patient had vascular compression of the spinal nerve rootlet without any venous congestion. CONCLUSIONS: Our experience shows that SDAVF can present not only as a myelopathy but also as a radiculopathy, indicating that radiculopathy may become a main symptom of SDAVF.

Treatment of Recurrent Intracranial Aneurysms After Clipping: A Report of 23 Cases and a Review of the Literature.

OBJECTIVE: There are no established treatment strategies for aneurysms that recur after clipping. In this study, we present cases of patients who experienced recurrent aneurysms after clipping and subsequently underwent surgical intervention. METHODS: Between 2004 and 2015, we surgically treated 23 aneurysms that recurred at a previously clipped site. Patient characteristics and clinical history were retrospectively reviewed. RESULTS: Patients included 19 women and 4 men 45-81 years old. Aneurysms recurred 3-31 years (mean, 15.4 years) after the initial operation. For 18 cases, the first clinical presentation was a subarachnoid hemorrhage; aneurysms were incidentally diagnosed in 5 patients. Aneurysm locations were as follows: 9 on the internal carotid artery; 4 on the middle cerebral artery; 7 on the anterior communicating artery; 2 on the distal anterior cerebral artery; and 1 on the basilar artery. The reasons for retreatment included subarachnoid hemorrhage (n = 9) and aneurysm regrowth detected on follow-up examinations (n = 14). Endovascular treatment was performed in 10 cases, and direct surgery was performed in 13 cases (clipping in 8, clipping or trapping with bypass in 5). Various complex vascular reconstructions, including high-flow bypass and intracranial-intracranial in situ bypass, were performed for recurrent aneurysms. CONCLUSIONS: In our experience, coil embolization is a safe and effective procedure for treating recurrent aneurysms. When cases are unsuitable for coil embolization, surgical treatment often requires neurosurgeons not only to overcome the general technical difficulty of reoperative clipping but also to perform challenging vascular reconstruction.

Surgical treatment of superior cluneal nerve entrapment neuropathy.

OBJECT: Superior cluneal nerve (SCN) entrapment neuropathy is a poorly understood clinical entity that can produce low-back pain. The authors report a less-invasive surgical treatment for SCN entrapment neuropathy that can be performed with local anesthesia. METHODS: From November 2010 through November 2011, the authors performed surgery in 34 patients (age range 18-83 years; mean 64 years) with SCN entrapment neuropathy. The entrapment was unilateral in 13 patients and bilateral in 21. The mean postoperative follow-up period was 10 months (range 6-18 months). After the site was blocked with local anesthesia, the thoracolumbar fascia of the orifice was dissected with microscissors in a distal-to-rostral direction along the SCN to release the entrapped nerve. RESULTS: were evaluated according to Japanese Orthopaedic Association (JOA) and Roland-Morris Disability Questionnaire (RMDQ) scores. Results In all 34 patients, the SCN penetrated the orifice of the thoracolumbar fascia and could be released by dissection of the fascia. There were no intraoperative surgery-related complications. For all patients, surgery was effective; JOA and RMDQ scores indicated significant improvement (p < 0.05). CONCLUSIONS: For patients with low-back pain, SCN entrapment neuropathy must be considered as a causative factor. Treatment by less-invasive surgery, with local anesthesia, yielded excellent clinical outcomes.

Giant cell tumor of the frontal bone in a girl: case report.

A 2-year-old female presented with a rare case of recurrent giant cell tumor affecting the frontal bone. She had already undergone partial removal twice at the ages of 14 and 18 months. The tumor was located in the frontal bone, expanding to the ethmoid and orbital bones, and invading the frontal base dura mater. The tumor was totally removed including the surrounding bone and frontal base dura mater. No local recurrence and metastasis were observed at 18 months after the last operation. Most giant cell tumors occur in the epiphyses of long bones and are rare in the cranio-facial bone. These tumors usually affect young adults and few pediatric cases are reported.