Intra- and Extra-Articular Deformity of Lower Limb: Tibial Condylar Valgus Osteotomy (TCVO) and Distal Tibial Oblique Osteotomy (DTOO) for Reconstruction of Joint Congruency.

Osteotomies are the established surgical procedure for the deformity of the lower limb induced by osteoarthritis (OA) of the knee and ankle. Closed-wedge (CW) and open-wedge (OW) high tibial osteotomy (HTO) are extra-articular surgery, which aim to shift the mechanical axis from medial to slightly lateral and reduce the overload in the medial compartment of the varus deformed knee by extra-articular correction. However, varus deformity of the knee with the teeter effect, which could be accompanied with subluxation and thrust due to the medial-lateral soft tissue imbalance, is not resolved only by the shift of mechanical axis. The depression of the medial tibia plateau, so-called pagoda deformity, is the intra-articular deformity, which could potentially cause the teeter effect and involves intra-articular incongruency. In such case, the osteotomy with novel concept should be developed to overcome the issues, both the imbalance of soft tissue and intra-articular deformity. Tibial condylar valgus osteotomy (TCVO) is an intra-articular osteotomy, which improves the joint congruency of the medial-compartment knee OA with subluxation and/or intra-articular deformity and also provides better joint stability. A similar argument is raised in the treatment of the ankle OA. Low tibial osteotomy (LTO) is an extra-articular surgery to correct malalignment of lower leg. Distal tibial oblique osteotomy (DTOO) is a novel surgery to improve the bony congruency of the ankle OA. In DTOO, the distal tibia is cut obliquely from the proximal medial to the distal lateral in the coronal plane and towards the center of the tibiofibular joint to improve the bony congruency of the ankle joint. Tibial condylar valgus osteotomy (TCVO) and distal tibial oblique osteotomy (DTOO) can correct intra-articular deformity of knee and ankle, respectively. The rationale and indication of TCVO and DTOO for the treatment of the lower limb by reconstructing the joint congruency are discussed.

Curative treatment of cerebral arteriovenous malformations by embolisation using cellulose acetate polymer followed by surgical resection.

AIM: To investigate the usefulness of embolising cerebral arteriovenous malformations (AVMs) with a cellulose acetate polymer solution before surgical resection. METHODS: The cases of 12 patients with AVMs treated by embolisation before surgical resection were renewed. Two types of cellulose acetate polymer solutions were used to occlude 40 feeding vessels. All patients underwent surgical resection 1-51 days after embolisation. RESULTS: Reduction of the nidus volume after embolisation ranged from 20% to nearly 100%. Transient neurological deficits occurred in three patients, persistent deficits occurred in one and there were no haemorrhagic complications. All but one arteriovenous malformation were completely resected. Embolisation helped to identify feeding vessels and ease dissection. Histopathological examination of resected specimens disclosed mild inflammatory reactions in the acute stage and no unfavourable granulomatous changes in the chronic stage. CONCLUSION: Embolisation with cellulose acetate polymer solutions followed by surgical resection is safe and efficacious for treating cerebral AVMs.

Combined use of cellulose acetate polymer and retrievable platinum coils for the thrombosis of cervical carotid aneurysms.

Cellulose acetate polymer (CAP) solution is a new liquid embolic material, and it has been used clinically for the thrombosis of cerebral aneurysms. The purpose of the study was to test a method of aneurysm treatment. In an experimental model, retrievable interlocking detachable coils (IDCs) were used to create an intraaneurysmal frame or prop and then CAP was injected into 20 experimentally induced canine cervical aneurysms. Intraaneurysmal thrombosis was induced 1 week after aneurysm creation. Complete thrombosis was attempted in 12 aneurysms, and partial thrombosis was attempted in 4. Four other aneurysms served as controls. Follow-up angiography was performed for up to 8 weeks, and with the exception of 4 aneurysms, which were kept for a 2-year long-term follow-up study, the aneurysms were then harvested for histological examination. Thrombosis was successfully achieved in all cases except for 2 enlarged aneurysms that were initially partially thrombosed. No thromboembolism to distal vessels was observed. No compaction or shift of the CAP-IDC complex occurred even after 2 years. Histologically, CAP and IDCs conformed to the massive thrombotic complex without any fragmentation. By creating a frame or prop with retrievable microcoils, we were able to inject the CAP implies a comparison safely and precisely than has been previously reported. Our findings suggest that this method will be useful for the treatment of cerebral aneurysms.

A Giant Glitch in the Energetic 69 Millisecond X-Ray Pulsar AXS J161730-505505.

We present new results on the recently discovered 69 ms X-ray pulsar AXS J161730-505505, the sixth youngest example of a rotation-powered pulsar. We have undertaken a comprehensive X-ray-observing campaign of AXS J161730-505505 with the ASCA, BeppoSAX, and RXTE observatories and follow its long-term spin-down history between 1989 and 1999 using these observations and archival Ginga and ASCA data sets. The spin-down is not simply described by a linear function as originally thought, but instead we find evidence of a giant glitch (DeltaP&solm0;P greater, similar10-6) between 1993 August and 1997 September, perhaps the largest yet observed from a young pulsar. The glitch is well described by steps in P and P&d2; accompanied by a persistent P&d3; similar to those seen in the Vela pulsar. The pulse profile of AXS J161730-505505 presents a single asymmetric peak that is maintained over all observation epochs. The energy spectrum is also steady over time, characterized by a highly absorbed power law with a photon index Gamma=1.4+/-0.2, consistent with that found for other young rotation powered pulsars.

Discovery of a New Pulsating X-Ray Source with a 1549.1 Second Period, AX J183220-0840.

A new pulsating X-ray source, AX J183220-0840, with a 1549.1 s period was discovered at R.A.=18h32m20s and decl.=-8&j0;40'30" (J2000, with an uncertainty of 0&farcm;6) during an ASCA observation on the Galactic plane. The source was observed two times, in 1997 and in 1999. A phase-averaged X-ray flux of 1.1x10-11 ergs cm-2 s-1 and a pulsation period of 1549.1+/-0.4 s were consistently obtained from these two observations. The X-ray spectrum was represented by a flat, absorbed power law with a photon index of Gamma approximately 0.8 and an absorption column density of NH approximately 1.3x1022 cm-2. Also, a signature of iron K-shell line emission with a centroid of 6.7 keV and an equivalent width of approximately 450 eV was detected. From the pulsation period and the iron-line feature, AX J183220-0840 is likely to be a magnetic white dwarf binary with a complexly absorbed thermal spectrum with a temperature of about 10 keV.

Intermittent propofol sedation during embolization of cerebral arteriovenous malformations.

Embolization procedure was performed for a 12-year-old boy with a left parietal arteriovenous malformation. Although provocative tests for the feeders to be occluded were considered very informative, the patient had to be sedated during microcatheter insertion. We used intermittent sedation with propofol during the interventional procedure, and obtained successful embolization.

The Reconstructions for Vertebral Artery Stenosis at the Origin. A Comparison between PTA and Surgical Reconstructions.

SUMMARY: To date in our hospital, surgical reconstructions and percutaneous transluminal angioplasty (PTA) were carried out in 168 patients with vertebral artery (VA) stenosis at the origin. In this article, we discuss the comparison between surgical reconstructions and PTA, especially regarding long term follow up, patency and complications. PTA is a less invasive treatment for VA stenosis at the origin than surgical reconstructions. However, restenosis after PTA occurred in 20% of the patients. On the other hand, restenosis after surgical reconstructions did not emerge even in long term follow up. An embolism after PTA occurred in 2.6% of the cases. However, the embolism occurred in only the first 10 patients of our series, after that there was no embolism. We concluded that PTA was the first choice for VA stenosis at the origin, if the angiogram did not reveal any PTA difficulty. If restenosis after PTA was performed, we selected surgical reconstruction for VA stenosis at the origin.

Embolization of cerebral arteriovenous malformations with cellulose acetate polymer: a clinical, radiological, and histological study.

OBJECTIVE: A cellulose acetate polymer (CAP) solution was hypothesized to be useful for the embolization of arteriovenous malformations (AVMs). To investigate this possibility, we analyzed the clinical, radiological, and histological results of patients with AVMs embolized by using a CAP solution. METHODS: We reviewed the cases of 11 patients with AVMs treated by embolization before surgical resection. We used two types of CAP solutions, CAP-M and CAP-L, which are mixtures of 250 mg of solid CAP and 1800 or 2250 mg of bismuth trioxide dissolved in 5.5 or 7.0 ml of dimethyl sulfoxide, respectively. After the embolization procedure, percent reduction of the nidus volume was measured, and thereafter, the clinical course and computed tomographic scans and/or magnetic resonance imaging scans were evaluated. All patients underwent surgical resection 1 to 51 days after embolization. Resected specimens were stained for light microscopic examination. RESULTS: Thirty-nine feeding vessels were embolized. The reduction rate of the nidus volume ranged from 20% to nearly 100%. Transient and persistent ischemic deficits occurred in three patients and one patient, respectively, and there were no hemorrhagic complications. All AVMs but one were completely resected by surgery. The embolized AVMs were soft enough to be easily cut and retracted. The histological examinations disclosed no or mild inflammatory reactions within 2 weeks after embolization. The internal elastic lamina was preserved in every case. Recanalization through the cast of the CAP mass was not observed until 51 days after embolization. CONCLUSION: CAP solution is a safe and useful embolic agent for AVMs.

Suitable image parameters and analytical method for quantitatively measuring cerebral blood flow volume with phase-contrast magnetic resonance imaging.

The aim of this study was to determine suitable image parameters and an analytical method for phase-contrast magnetic resonance imaging (PC-MRI) as a means of measuring cerebral blood flow volume. This was done by constructing an experimental model and applying the results to a clinical application. The experimental model was constructed from the aorta of a bull and circulating isotonic saline. The image parameters of PC-MRI (repetition time, flip angle, matrix, velocity rate encoding, and the use of square pixels) were studied with percent flow volume (the ratio of actual flow volume to measured flow volume). The most suitable image parameters for accurate blood flow measurement were as follows: repetition time, 50 msec; flip angle, 20 degrees; and a 512 x 256 matrix without square pixels. Furthermore, velocity rate encoding should be set ranging from the maximum flow velocity in the vessel to five times this value. The correction in measuring blood flow was done with the intensity of the region of interest established in the background. With these parameters for PC-MRI, percent flow volume was greater than 90%. Using the image parameters for PC-MRI and the analytical method described above, we evaluated cerebral blood flow volume in 12 patients with occlusive disease of the major cervical arteries. The results were compared with conventional xenon computed tomography. The values found with both methods showed good correlation. Thus, we concluded that PC-MRI was a noninvasive method for evaluating cerebral blood flow in patients with occlusive disease of the major cervical arteries.

Experimental study of intracisternal administration of tissue-type plasminogen activator followed by cerebrospinal fluid drainage in the ultra-early stage of subarachnoid haemorrhage.

This experimental study evaluated the effect of intrathecal injection of tissue-type plasminogen activator followed by cisternal drainage in the ultra-early stage of aneurysmal subarachnoid haemorrhage to prevent vasospasm. Twenty Japanese white rabbits were divided into five groups. Either tPA (groups A, B, and E) or saline (groups C and D) was injected intrathecally 1 hour (groups A, B, C, and D) or 21 hours (group E) after the intrathecal injection of blood. Cerebrospinal fluid was drained 2, 4, and 6 hours after the intrathecal injection of blood (groups A, C, and E). On day 4, the angiographic caliber of the basilar artery in each group was as follows (mean +/- SD): A, 85.9 +/- 5.0%; B, 74.6 +/- 5.3%; C, 69.1 +/- 2.7%; D, 64.0 +/- 4.9%; E, 80.2 +/- 2.7% (compared with baseline). In the two groups in which CSF was drained (groups A and C), fibrinolysis with tPA significantly suppressed vasospasm. In the two groups treated with tPA (groups A and B), cisternal drainage significantly suppressed vasospasm. In the two groups treated with saline (groups C and D), however, cisternal drainage did not suppress vasospasm. Examination of the series of CSF samples (groups A and C) showed that fibrinolysis with tPA effectively cleared clots early. In the two groups treated with tPA and CSF drainage (groups A and E), early removal of subarachnoid clots reduced the degree of vasospasm. Early fibrinolysis with tPA and early removal of subarachnoid clots by drainage is effective for preventing vasospasm.

Partial thrombosis of canine carotid bifurcation aneurysms with cellulose acetate polymer.

OBJECTIVE: To investigate the usefulness of a cellulose acetate polymer (CAP) solution for partial thrombosis of aneurysms. METHODS: We created 14 canine cervical carotid bifurcation aneurysms, 11 of which were subsequently thrombosed partially with CAP solution. We then conducted angiographic and histological investigations. RESULTS: Nine aneurysms were thrombosed 50 to 70% by volume, although a significant crescent crevice between the aneurysmal sac and the CAP mass was left in four of the aneurysms. In the remaining two aneurysms in which a crescent crevice had been seen in the initial stage of CAP injection, 80% and more than 95% thrombosis were needed to occlude the crevice, respectively. Follow-up angiograms of the seven aneurysms with no crescent crevice revealed no shifts of position of the CAP mass toward the bottom of the aneurysm sac, but slight ballooning of the remnants was observed in two of them. The angiograms of the other four aneurysms with significant crescent crevices demonstrated rupture with a massive hematoma in one and shifts of the CAP mass with marked enlargement of remnants in three. Histologically, the seven aneurysms with no enlarged remnants had newly developed membranes consisting of endothelium, infiltrated spindle-shaped cells, collagen, and elastic fibers. In contrast, in the three markedly enlarged aneurysms, there were only recent clots between the CAP mass and the aneurysm lumen and no development of endothelium. CONCLUSION: Partial thrombosis with CAP solution is useful to keep aneurysms in a stable configuration, unless a crescent crevice has been left.

Six cases of ruptured aneurysm, treated with cellulose acetate polymer.

SUMMARY: We review 6 cases of ruptured aneurysm which were elderly, poor-grade SAH or requiring high-risk surgery treated with Cellulose Acetate Polymer (CAP). A 76-year-old female with A-com aneurysm was comatose. Heart failure was her complication (case 1). An 81-year-old female with A-com aneurysm was semicomatose (case 2). An 89-year-old female with MCA aneurysm was semicomatose and had right hemiplegia (case 3). An 88-year-old female with MCA aneurysm was comatose (case 4). A 55-year-old male with IC-PC aneurysm had a small intracerebral hematoma and was semicomatose (case 5). A 52-year-old female with IC-Ach aneurysm was somnolent (case 6). All cases had no rebleeding after embolization. CAP embolization was complete in all cases but case 1. Case 4 died from primary brain damage on the day 7. Three cases stayed in a severely disabled state and died after 3 months (case 1), 2 months (case 2) and 4 months (case 3) from onset respectively. Case 5 remains in a moderately disabled state after 2 years. Case 6 had a anterior choroidal artery which was hard to spare on aneurysmal clipping. She is free from neurological deficits after CAP embolization. Angiography after 2 years demonstrated complete obstruction of the aneurysm. CAP is good for cases which are elderly, poorgrade SAH or difficult to treat with surgery. CAP embolization has some advantages over GDC coil obstruction for aneurysm treatment.

Embolization of cerebral arteriovenous malformations with cellulose acetate polymer. Histological study of the resected specimens.

SUMMARY: To test the usefulness of a cellulose acetate polymer(CAP) solution for brain arteriovenous malformations (AVMs), we analyzed the clinical and histological results of patients with AVMs embolized using CAP solution. We reviewed the cases of six patients with cerebral AVMs treated by embolization prior to surgical resection. We used two types of CAP solutions, CAP-M and CAP-L, which are mixtures of 250 mg of solid CAP and 1800 or 2250 mg of bismuth trioxide dissolved in 5.5 or 7.0 ml of dimethyl sulfoxide, respectively. All patients underwent surgical resection 1 to 37 days after the embolization procedure. Resected specimens were fixed in formalin and stained for light microscopic examination. Eighteen feeding vessels were embolized. The reduction rate of the nidus volume was between 20% and nearly 100%. Mild ischemic deficits occurred in one patients but there were no hemorrhagic complications related to the embolization procedures. All AVMs were completely resected by surgery. Direct inspection at surgery revealed that there was no apparent swelling or hematomas in the normal brain areas adjacent to the nidus, and the AVMs were soft enough to be easily retracted. The histological examinations disclosed no or mild inflammatory reactions within two weeks after embolization. The internal elastic lamina was preserved in every case. Recanalization of embolized vessels was not observed until 37 days after embolization. CAP solution is a safe and useful embolic agent for brain AVMs. Further study is needed to resolve the issue of recanalization.

An in vitro study to define the term "dense packing" of aneurysms with detachable coils, liquid embolic material and their combination.

SUMMARY: The purpose of this study was to define the terms minimal and maximal "dense packing" of a given cavity with platinum coils and liquid material (cellulose acetate polymer; CAP) using precise in vitro volumetric methods. Tests were performed using a simple in vitro aneurysm model, precisely measured in volume and thereafter filled with platinum coils and/or CAP. The volume of the aneurysmal cavity was measured with a very precise special micropump. The volume of each platinum coil (GDC) was also calculated. Minimal dense packing was defined as the point where there was angiographic evidence of complete filling of the cavity and exclusion from the parent lumen of the aneurysm. Maximal dense packing was defined as the point where introduction of additional coils resulted in their protrusion into the parent artery. At minimal dense packing the ratio of aneurysm volume to coil volume ranged from 25.97% to 32.50%. At maximal dense packing the ratio ranged from 29.55% to 36.16%. The volumetric ratio ofminimal and maximal dense packing obtained was lower than we had expected. The volumetric ratio with CAP was 106.08% and 126.08% and the ratio obtained by the combined use of coils and CAP ranged from 103.78% to 140.2%. When the volumetric ratio of the packing is much lower than the ratio of dense packing by rough estimate, we should expect coil compaction and careful follow-up should be done. Liquid material filled the lumen more densely and the additional use of liquid may be useful to prevent coil compaction.

[Motor functional MRI by spiral scan--compared with GRE].

Recently, functional MRI (fMRI) has been performed in two methods using 1.5 tesla machine. One was performed using gradient recalled echo (GRE), the other was performed using echo planner imaging (EPI). There is a third method for fMRI called spiral scan. This method is applicable without strong gradient magnetic field such as required by EPI. In this study, motor fMRI was performed in ten normal volunteers by both spiral scan and GRE. Less than 1% risk (t-test), spiral scan showed the reactive area more clearly than GRE. And GRE showed higher signal intensity changing ratio than spiral scan, but there was no significant difference between spiral scan and GRE. The acquisition time of spiral scan was 2 seconds per image, and that of GRE was 10.5 seconds. Spiral scan has good temporal resolution and contrast-noise ratio. These are very advantageous for fMRI.

Histopathology and clinical results of carpal tunnel syndrome in idiopathic cases and hemodialysis patients.

The results of the histological examinations of specimens of the tenosynovium of the flexor tendon, the epineurium and the transverse carpal ligament from two groups of Japanese patients with carpal tunnel syndrome (idiopathic and hemodialysis) were compared. Amyloid deposits, positively identified as beta 2-microglobulin, appeared in all patients in the long-term hemodialysis group, but in no patients in the idiopathic group. Although the pathogenesis differed between the two groups, both resulted in nerve compression in the carpal tunnel. Therefore, surgical release is considered beneficial for both groups.

Fistula of the posterior communicating artery and cavernous sinus.

A 24-year-old man was admitted with conjunctival hyperemia of the left eye and progressive chemosis and proptosis 1 month after a head injury. An angiogram showed an arterial-cavernous sinus fistula of the posterior communicating artery, which was treated with minicoils. The atypical configuration, transvenous embolization, and unusual nature of the communication suggested that communication developed through a newly generated vessel in granulation tissue.

Direct thrombosis of experimental aneurysms with cellulose acetate polymer (CAP): technical aspects, angiographic follow up, and histological study.

Experimental aneurysms were created using a microsurgical technique to produce anastomosed venous pouches in the bilateral common carotid arteries of 12 dogs. The 24 aneurysms were then thrombosed via an endovascular approach with injection of a cellulose acetate polymer (CAP) solution that the authors have developed for use as a liquid thrombotic material. Angiography performed 1 to 4 weeks after CAP injection revealed complete thrombosis of the aneurysm with patency of the parent artery in 16 aneurysms. Histological analysis disclosed that the aneurysmal orifice in these cases was completely covered with newly formed endothelial cells 2 weeks after CAP thrombosis. Three other aneurysms exhibited parent artery occlusion caused by protrusion of the CAP mass through the aneurysmal orifice into the parent artery; this was thought to be caused by over-injection of the CAP solution. Histological analysis of the remaining five aneurysms, initially shown to have incomplete occlusion, revealed that they each possessed a residual neck that was partially covered with endothelial cells. No rupture of the aneurysms or migration of CAP into the distal arteries was observed. These results suggest that using an endovascular approach, direct thrombosis of cerebral aneurysms with CAP is safe and effective. This technique may prove to be an alternative treatment for such aneurysms. However, there is a potential risk of regrowth or rupture of aneurysms that retain a residual neck and long-term follow-up studies will be required to evaluate this issue.

Early treatment of subarachnoid hemorrhage after preventing rerupture of an aneurysm.

Twelve patients with Hunt and Hess neurological Grades III to V underwent thrombosis of aneurysms using cellulose acetate polymer within 23 hours of aneurysm rupture. On computerized tomography (CT), nine of these patients had difuse or localized thick subarachnoid blood clots, two had diffuse thin clots and one had intraventricular clots. Immediately after thrombosis, all patients were administered tissue plasminogen activator (TPA) through spinal or ventricular catheters. The pressure of the lumbar cerebrospinal fluid was maintained at 100 to 150 mm H2O. The TPA was given as multiple injections of 2 mg on Day 0 and 1 to 2 mg on the following 1 to 2 days. In two patients the second injection of TPA was not given because of severe brain damage resulting from the initial subarachnoid hemorrhage. Ten patients showed complete clearance of the cisternal clot on CT within 72 hours after thrombosis. Seven partially thrombosed aneurysms and five multiple aneurysms were clipped during delayed surgery. Only one patient experienced mild vasospasm as shown on the follow-up angiogram. Eight patients improved clinically and had a good recovery, two had severe disability, and two died. Urgent thrombosis of a ruptured aneurysm followed by immediate postthrombotic administration of TPA may be a safe and reasonable means of preventing vasospasm and improving patient outcome.