Brain-derived endothelial cells are neuroprotective in a chronic cerebral hypoperfusion mouse model.

Whether organ-specific regeneration is induced by organ-specific endothelial cells (ECs) remains unelucidated. The formation of white matter lesions due to chronic cerebral hypoperfusion causes cognitive decline, depression, motor dysfunction, and even acute ischemic stroke. Vascular ECs are an important target for treating chronic cerebral hypoperfusion. Brain-derived ECs transplanted into a mouse chronic cerebral hypoperfusion model showed excellent angiogenic potential. They were also associated with reducing both white matter lesions and brain dysfunction possibly due to the high expression of neuroprotective humoral factors. The in vitro coculture of brain cells with ECs from several diverse organs suggested the function of brain-derived endothelium is affected within a brain environment due to netrin-1 and Unc 5B systems. We found brain CD157-positive ECs were more proliferative and beneficial in a mouse model of chronic cerebral hypoperfusion than CD157-negative ECs upon inoculation. We propose novel methods to improve the symptoms of chronic cerebral hypoperfusion using CD157-positive ECs.

Association of Gut Microbiome with Early Brain Injury After Subarachnoid Hemorrhage: an Experimental Study.

The occurrence of early brain injury (EBI) following subarachnoid hemorrhage (SAH) is crucial in the prognosis of SAH; however, no effective treatment for EBI has been developed. Gut microbiome (GM) composition influences the outcome of various diseases, including ischemic stroke. Here, we evaluated whether prior GM alteration could prevent EBI following SAH. We altered the GM of 7-week-old male rats by administering antibiotic-containing water for 2 weeks and performing fecal microbiome transplantation after antibiotic induction. Composition of the GM was profiled using 16S rRNA. We induced SAH by injecting blood in the subarachnoid space of control rats and rats with altered GM. We evaluated EBI indicators such as neurological score, brain water content, Evans blue extravasation, and neuronal injury. Additionally, we studied inflammatory cells using immunohistochemistry, immunocytochemistry, quantitative PCR, and flow cytometry. EBI was significantly averted by alterations in GM using antibiotics. The altered GM significantly prevented neutrophil infiltration into the brain among inflammatory cells, and this anti-inflammatory effect was observed immediately following SAH onset. The altered GM also prevented neutrophil extracellular trap formation in the brain and blood, indicating the systemic protective effect. The cause of the protective effect was attributed to a significant decrease in aged neutrophils (CXCR4high CD62Llow) by the altered GM. These protective effects against EBI disappeared when the altered GM was recolonized with normal flora. Our findings demonstrated that EBI following SAH is associated with GM, which regulated neutrophil infiltration.

Dysbiosis of Gut Microbiome Is Associated With Rupture of Cerebral Aneurysms.

BACKGROUND AND PURPOSE: Environmental factors are important with respect to the rupture of cerebral aneurysms. However, the relationship between the gut microbiome, an environmental factor, and aneurysm rupture is unclear. Therefore, we compared the gut microbiome in patients with unruptured intracranial aneurysms (UIAs) and ruptured aneurysms (RAs) to identify the specific bacteria causing the rupture of cerebral aneurysms. METHODS: A multicenter, prospective case-control study was conducted over one year from 2019 to 2020. The fecal samples of patients with stable UIAs and RAs immediately after onset were collected. Their gut microbiomes were analyzed using 16S rRNA sequencing. Subsequently, a phylogenetic tree was constructed, and polymerase chain reaction was performed to identify the specific species. RESULTS: A total of 28 RAs and 33 UIAs were included in this study. There was no difference in patient characteristics between RAs and UIAs: age, sex, hypertension, dyslipidemia, diabetes status, body mass index, and smoking. No difference was observed in alpha diversity; however, beta diversity was significantly different in the unweighted UniFrac distances. At the phylum level, the relative abundance of Campylobacter in the RA group was larger than that in the UIA group. Furthermore, the gut microbiome in the RA and UIA groups exhibited significantly different taxonomies. However, Campylobacter was focused on because it is widely known as pathogenic among these bacteria. Then, a phylogenetic tree of operational taxonomic units related to Campylobacter was constructed and 4 species were identified. Polymerase chain reaction for these species identified that the abundance of the genus Campylobacter and Campylobacter ureolyticus was significantly higher in the RA group. CONCLUSIONS: The gut microbiome profile of patients with stable UIAs and RAs were significantly different. The genus Campylobacter and Campylobacter ureolyticus may be associated with the rupture of cerebral aneurysms.

Ophthalmic Artery Flow Pattern-related Stump Pressure and Ischemic Tolerance during Balloon Test Occlusion of the Internal Carotid Artery.

Very few studies have described the blood flow pattern in the ipsilateral ophthalmic artery (OphA) during internal carotid artery (ICA) balloon test occlusion performed to estimate the risk of cerebral ischemia associated with therapeutic ICA sacrifice. This study aimed to investigate the relationship between ipsilateral OphA flow patterns just after ICA temporary occlusion and balloon test occlusion findings. We retrospectively reviewed 32 balloon test occlusion procedures performed at our institution between 2010 and 2019, and analyzed the OphA flow patterns and the conventional balloon test occlusion assessment items: neurological symptoms, stump pressure, stump-pressure ratio, collateral circulations, and venous phase delay. The flow patterns were categorized as type I (retrograde flow reaching the middle cerebral artery [MCA]), type II (retrograde flow to the ICA not reaching the MCA), or type III (no retrograde flow). Tolerance to balloon test occlusion was observed in 4/21 patients (19.0%), 4/6 patients (66.7%), and all five patients with types I, II, and III flows, respectively. The mean pressure ratios during balloon test occlusion in flow types I, II, and III were 35.6% ± 3.5%, 56.4% ± 6.5%, and 69.4% ± 7.1%, respectively (P <0.001). The mean stump pressures in flow types I, II, and III were 36.2 ± 3.6 mmHg, 46.6 ± 6.7 mmHg, and 66.6 ± 7.3 mmHg, respectively (P = 0.003). The mean venous phase delay in flow types I, II, and III were 0.99 ± 0.14 s, 0.25 ± 0.25 s, and 0.0 ± 0.28 s, respectively (P = 0.004). All the above variables showed significant flow-related differences. These results suggest that the OphA flow patterns may provide an additional diagnostic criterion for balloon test occlusion.

Carotid artery stenting before surgery for carotid artery occlusion associated with acute type A aortic dissection: Two case reports.

BACKGROUND: We experienced two cases of ischemic stroke resulting from carotid artery occlusion associated with acute type A aortic dissection (ATAAD), in which carotid artery stenting before the surgery for ATAAD resulted in good clinical outcomes.Case 1 description: A 63-year-old woman was hospitalized for conscious disturbance, right hemiparesis, and total aphasia. Computed tomography of the head showed no abnormal findings. Computed tomography angiography showed ATAAD and bilateral common carotid artery occlusion. Surgery was not indicated for ATAAD because of a poor prognosis of ischemic stroke. However, carotid artery stenting of the left common carotid artery occlusion was successfully performed, and her neurological findings improved. The patient underwent hemiarch replacement for ATAAD on the day after carotid artery stenting. Her final modified Rankin Scale was 1. Case 2 Description: A 57-year-old woman was hospitalized for mild left hemiparesis. Magnetic resonance imaging showed right watershed infarction and right common carotid artery occlusion. Computed tomography angiography showed ATAAD. After hospitalization, conscious disturbance appeared and left hemiparesis worsened. Ischemic stroke indicated a poor prognosis for revascularization by surgery for ATAAD. Thus, carotid artery stenting of the right common carotid artery occlusion was performed. The patient's neurological findings improved and she underwent hemiarch replacement for ATAAD at 19 days after carotid artery stenting. Her final modified Rankin Scale was 1. CONCLUSIONS: In the present cases, although ischemic stroke was serious and precluded surgical indication for ATAAD, carotid artery stenting before surgery for ATAAD resulted in good clinical outcomes. Performing carotid artery stenting before surgery for ATAAD is challenging but achievable, and is a valid treatment option depending on the individual cases.

Outcomes of Endovascular Therapy versus Microsurgical Treatment for Aneurysmal Subarachnoid Hemorrhage in Patients ≥70 Years of Age.

Purpose: This retrospective research aimed to compare the efficacy of endovascular therapy (EVT) versus microsurgical treatment (MST) for elderly patients with aneurysmal subarachnoid hemorrhage (aSAH). Methods: Elderly (>70 years) patients with aSAH who underwent aneurysm obliteration during 2007-2017 were selected from our hospital database and enrolled in this retrospective study. We reviewed each patient's background, the severity of the aSAH, and aneurysmal characteristics that compelled EVT or microsurgery treatment and then compared the two treatment groups. A favorable primary outcome was defined by a modified Rankin scale (mRS) score of 0-3 at hospital discharge. The 78 patients formed two cohorts (39 patients each) based on their propensity scores for EVT or MST. We estimated the adjusted odds ratio, followed by a sensitivity analysis of the original 201 patients (118 with EVT and 83 with MST). Results: In the propensity score-matched cohorts, favorable outcomes were observed in 33.3% and 7.7% of patients in the EVT and MST groups, respectively (p = 0.01). Results of the sensitivity analysis were similar to the main results. Conclusion: The clinical outcomes for the elderly aSAH patients were better in the EVT group than in MST group.

A Case of Subarachnoid Hemorrhage with Dissecting Aneurysm of the Anterior Choroidal Artery.

Objective: Dissecting aneurysms of the anterior choroidal artery (AchoA) are extremely rare, with only a few reported cases. Herein, we report an extremely rare case of subarachnoid hemorrhage with dissecting aneurysm of the AchoA. Case Presentation: A 68-year-old man was hospitalized for sudden onset of headache, progressive consciousness disorder, and right hemiparesis. He had a prior medical history of systemic lupus erythematosus (SLE), and was taking prednisolone (50 mg/day) for 15 months. CT showed subarachnoid hemorrhage in the left side of the basal cistern and Sylvian fissure. Left internal carotid artery (ICA) angiography revealed a fusiform aneurysm of the AchoA. He was diagnosed with a ruptured dissecting aneurysm of the AchoA because the shape of aneurysm was fusiform and there was laminar flow inside the aneurysm. Parent artery occlusion (PAO) was performed to prevent re-hemorrhage on the day of onset. Although ventricular drainage for acute hydrocephalus was performed after AchoA occlusion, his consciousness disorder did not improve. Postoperative angiography at 1-week recovery from the procedure revealed disappearance of the AchoA, including the dissecting aneurysm. However, he died following septic shock caused by pneumonia at 1 month after the procedure. Conclusion: We report an extremely rare case of subarachnoid hemorrhage with a dissecting aneurysm of the AchoA. Vasculitis caused by SLE and a vulnerability of the vessel wall following chronic steroid use are potential causes of the dissecting aneurysm of the AchoA.

Safety and efficacy of an open-cell stent and double-balloon protection for unstable plaques: analysis of 184 consecutive carotid artery stentings.

INTRODUCTION: In our institute, most cases of carotid artery stenosis are treated by carotid artery stenting (CAS) with an open-cell stent and double-balloon protection, even if plaques are unstable. This study was performed to examine the outcome of CAS with an open-cell stent and double-balloon protection for unstable plaques. METHODS: A total of 184 CAS procedures in our institute between October 2010 and February 2018 were assessed. Ultrasonography findings of low-echo plaques, plaque ulceration, or both were defined as unstable plaques. A plaque-to-muscle ratio (PMR) of >1.8 on T1-weighted black blood imaging using spin-echo was also defined as an unstable plaque. Seventy-four unstable plaques on ultrasonography and 86 unstable plaques evaluated by PMR were included. Open-cell stents and double-balloon protection (proximal balloon protection during lesion crossing and distal balloon protection after lesion crossing) were used in all cases. RESULTS: On ultrasonography, perioperative asymptomatic thromboembolization was significantly more frequent in the unstable plaque group (39/74, 52.7%) than in the stable plaque group (41/110, 37.3%, p=0.0384). Asymptomatic thromboembolization was also significantly more frequent in the PMR >1.8 group (44/86, 51.2%) than in the PMR <1.8 group (36/98, 36.7%, p=0.0489). However, symptomatic thromboembolization was rare (n=5, 2.7%), and all of these patients had minor stroke. During the 4-year follow-up, the risk of ipsilateral stroke was 0.28% and 0.27% per year in patients with symptomatic and asymptomatic lesions, respectively. CONCLUSIONS: The outcomes of CAS with an open-cell stent and double-balloon protection are acceptable. This method is effective and safe, even if carotid artery stenosis comprises unstable plaques.

[Treatment Strategies for Unruptured Multiple Intracranial Aneurysms].

OBJECTIVE: Unruptured aneurysms are often discovered incidentally on MRI. In some patients, multiple aneurysms cannot be treated with only craniotomy or endovascular surgery. When both craniotomy and endovascular surgery are deemed necessary, craniotomy is generally performed first because of the use of antiplatelet agents involved, followed by endovascular surgery several months later. However, no clear criteria for this treatment policy have been elicited. We investigated therapeutic outcomes in patients with aneurysms treated by craniotomy followed by endovascular surgery at our hospital. PATIENTS AND METHODS: This was a retrospective study including patients undergoing craniotomy clipping of one or more unruptured aneurysms at one site and endovascular surgery for those at a different site, between January 2012 and May 2018 in our hospital. The types of treatment, interval between treatments, complications, and other factors were analyzed. RESULTS: This study included 22 patients who underwent a total of 25 craniotomies and 23 endovascular surgeries. The mean time from final craniotomy to initial endovascular surgery was 118 days. Although treatment-related complications occurred in three patients, they were not associated with the time interval between craniotomy and endovascular surgery or the timing of the start of the antiplatelet therapy. CONCLUSIONS: The treatment was successful and was carried out safely and appropriately by first performing the craniotomy, followed by a set interval of time before starting the antiplatelet therapy, and then performing the endovascular surgery. Further studies analyzing more cases are required to establish the criteria better, such as the appropriate interval time between treatments.

Effect of Direct Neurologic Evaluation on Outcomes During Treatment of Unruptured Intracranial Aneurysms Under Local Anesthesia.

OBJECTIVE: The greatest advantage of local anesthesia (LA) in endovascular treatment (EVT) of unruptured intracranial aneurysms (UIAs) is that direct neurologic evaluation can be performed during the procedure, unlike with general anesthesia. However, the usefulness of such direct evaluation has not been established. In this study, we attempted to assess the effects of direct neurologic evaluation by identifying the causes, management, and outcomes of clinical symptoms during the procedure and procedure-related events during EVT under LA. METHODS: We retrospectively evaluated the medical and radiologic data of 1000 patients (1015 UIAs) who had undergone coil embolization under LA from 2008 to 2016. RESULTS: Clinical symptoms were identified in 62 patients (6.2%) during the procedure. The symptoms improved during the procedure in 27 of these patients (44%) and after the procedure in another 28 (45%). One month after the procedure, 55 patients (89%) had good outcomes and 7 (11%) had poor outcomes. Procedure-related events occurred in 67 patients (6.7%); of these 67 events, 39 were symptomatic and 28 were asymptomatic. Thirty-five of the 39 symptomatic events (90%) [13 of 13 (100%) ruptures, 6 of 10 (60%) thrombus formations, and 16 of 16 (100%) thromboembolisms] were detected on the basis of clinical symptoms before angiographic changes were identified, and they were managed promptly. All 28 patients with asymptomatic events were managed safely without further complications before symptoms developed. CONCLUSIONS: We demonstrated that appropriate management of clinical symptoms and procedure-related events under LA led to favorable outcomes of EVT of UIAs.

PulseRider-Assisted Coil Embolization for Treatment of Intracranial Bifurcation Aneurysms: A Single-Center Case Series with 24-Month Follow-up.

BACKGROUND: Although endovascular coiling of unruptured aneurysms is widely accepted, the endovascular treatment of wide-neck bifurcation aneurysms remains one of the most challenging morphologies. Our purpose was to describe our experience with 24-month follow-up for the treatment of unruptured intracranial bifurcation aneurysms using the PulseRider (Cerenovus, New Brunswick, NJ). METHODS: This study is a single-center, single-arm registry performed under institutional review board control to evaluate efficacy and safety of the PulseRider. Patients with bifurcation aneurysms were identified and enrolled prospectively. Angiography immediately after treatment and at 6 months, and magnetic resonance imaging and magnetic resonance angiography at 12- and 24-month follow-up were retrospectively analyzed. A modified Rankin score was obtained prior to procedure, at discharge, and at 6-, 12- and 24-month follow-up visits. RESULTS: Eight patients with a mean age of 66 years were treated with the PulseRider. All patients had bifurcation aneurysms (2 anterior communicating, 2 carotid terminus, and 4 basilar apex). The aneurysm diameters ranged from 4.6 to 13.6 mm (mean 7.4 mm) with dome/neck ratio ranging from 1.4 to 2.2 (mean 1.6). In all cases, the PulseRider was successfully deployed. Complete occlusion was demonstrated at 6-month follow-up on 6 of 8 (75%), near complete occlusion in 1 of 8 (12.5%), and residual aneurysm in 1 of 8 (12.5%) patients. There was no change or recurrence on magnetic resonance angiography, nor clinical complication after the procedure through 24-month follow-up. CONCLUSIONS: Our experience with 24-month follow-up demonstrated favorable efficacy in the treatment of intracranial wide-neck bifurcation aneurysms using the PulseRider.

Progressive thrombosis of unruptured aneurysms after coil embolization: analysis of 255 consecutive aneurysms.

INTRODUCTION: We have observed that aneurysms treated by insufficient coil embolization and filled with contrast agent immediately after the procedure are often completely occluded at follow-up. However, there are limited studies showing progressive thrombosis of aneurysms after coil embolization. Herein, we describe our experience with coil embolization for aneurysms, and discuss the factors involved in progressive thrombosis. METHODS: A total of 255 aneurysms treated by coil embolization in our institute between January 2011 and June 2017 and observed >6 months were included. 'Progressive thrombosis' indicated that aneurysms that were neck remnant (NR) or dome filling (DF) immediately after coil embolization changed to complete obliteration (CO) at the 6-month follow-up digital subtraction angiography. The factors involved in progressive thrombosis were assessed. RESULTS: In all aneurysms (n=255), 24 (9.4%) were CO, 82 (32.2%) were NR, and 149 (58.4%) were DF immediately after the procedure. At 6-month digital subtraction angiography, 123 (48.2%) were CO, 95 (37.3%) were NR, and 37 (14.5%) were DF. Retreatment for major recanalization was performed in eight cases (3.1%). One hundred and three aneurysms showed progressive thrombosis. There were significant differences in aneurysm location (P=0.0002), aneurysm dome diameter (P=0.0015), aneurysm neck diameter (P=0.0068), volume embolization ratio (P=0.0054), and endovascular procedure with stent (P=0.0264) between the progressive thrombosis and no thrombosis groups. CONCLUSIONS: Progressive thrombosis can occur in aneurysms after coil embolization depending on aneurysm location and size, and stent use. Thus, the degree of coil embolization and combination with a stent should be adjusted depending on aneurysm type.

Effect of Straightening the Parent Vessels in Stent-Assisted Coil Embolization for Anterior Communicating Artery Aneurysms.

BACKGROUND: Stent-assisted coil embolization (SAC) for treating anterior communicating artery (AcomA) aneurysms is safe and effective. Straightening of parent vessels by stent placement can lead to progressive thrombosis. We describe our experience with SAC for AcomA aneurysms and demonstrate the effect of straightening the parent vessels. METHODS: A total of 26 patients with AcomA aneurysms were treated using SAC in our institute between July 2010 and December 2017. Follow-up digital subtraction angiography was performed 6 months after treatment, magnetic resonance angiography was performed every year, and outcomes were analyzed. RESULTS: From all aneurysms (n = 24), 12 (50.0%) were neck remnant, and 12 (50.0%) were dome-filling types immediately after the procedure. At the 6-month digital subtraction angiography follow-up (n = 22), 13 (59.1%) aneurysms were complete obliteration, 8 (36.4%) were neck remnant, and 1 (4.5%) was dome filling. The median parent vessel angle was measured preoperatively at 98.1°, increased to 124.8° immediately after stent deployment, and further increased to 149.6° at the 6-month follow-up. Progressive thrombosis was observed in 13 of 22 (59.1%) aneurysms. The parent vessel angle change immediately after stent deployment in the progressive thrombosis group tended to be larger than that observed in the no thrombosis group; this change was significant at the 6-month follow-up. The median follow-up term was 18 months. No patients required retreatment. CONCLUSIONS: Good SAC outcomes were achieved for AcomA aneurysms, and hemodynamic changes related to straightening of the parent vessels is a consideration in SAC.

Comparison of practical methods in clinical sites for estimating cerebral blood flow during balloon test occlusion.

OBJECTIVE: The authors sought to compare methods of measurement for venous phase delay (VPD) or mean stump pressure (MSTP) to rank their potential to predict ischemic tolerance during balloon test occlusion in the internal carotid artery, exploring a more correlative and convenient way to measure cerebral blood flow (CBF) that could be utilized even in the acute phase or in institutions not adequately equipped to measure CBF during the test. METHODS: X-ray angiography perfusion analysis using diagnostic digital subtraction angiography (DSA) equipment enables 1-step examination (without any room-to-room transfer of patients) to measure CBF, VPD, and MSTP completely simultaneously, which has not been accomplished by any previous perfusion studies. RESULTS: This analysis was applied to 17 patients and resulted in successful estimation of all 3 parameters in each case. The average VPD of several cortical veins had a strong correlation with relative CBF (rCBF) between bilateral hemispheres with a correlation coefficient of 0.89443, a correlation as strong as that (0.90357) of the "approximate VPD," which is interpreted based on the trend line of the scatterplot of the time to peak contrast opacification in cortical veins and their spatial positioning from the median sagittal plane. MSTP and classic visual determination of VPD have weaker correlation coefficients with rCBF (0.56119 and 0.70048, respectively). Overall, subjective visual determination in combination with the calculation of the trend line to estimate VPD provided a considerably strong correlation with rCBF (R = 0.86660) without any dedicated software or hardware. CONCLUSIONS: VPD has a stronger correlation with rCBF than MSTP. rCBF could be successfully predicted on common DSA equipment, even by visual determination without expensive software, if the trend line is adopted for processing to estimate VPD.

Laparoscopic treatment of a vesicointestinal fistula due to a Meckel's diverticulum: a case report and review of the literature.

While there have been numerous reports about colovesical fistulas and ruptured intestinal diverticula, there have been far fewer reports about vesicointestinal fistulas caused by Meckel's diverticula. Most Meckel's diverticula are asymptomatic. Furthermore, they seldom cause vesicointestinal fistulas, and the associated complications are non-specific. Thus, their preoperative diagnosis is difficult. We experienced a case in which a vesicointestinal fistula was caused by a Meckel's diverticulum and was treated with laparoscopic surgery. A 46-year-old male was referred to our hospital after exhibiting hematuria. Cystoscopy revealed a fistula between the small intestine and bladder. Contrast-enhanced computed tomography and magnetic resonance imaging showed a diverticulum in the ileum and a fistula between the ileum and bladder, which passed through the diverticulum. A Meckel's diverticulum was suspected. We conducted a laparoscopic operation. We dissected the Meckel's diverticulum with an automatic suturing device and removed it together with part of the ileum. The patient's postoperative course was good. We experienced a case in which a vesicointestinal fistula was caused by a Meckel's diverticulum and was successfully treated with laparoscopic surgery. In selected cases of Meckel's diverticulum, the dissection of the diverticulum with an automatic suturing device is appropriate.

[Two Cases of Ruptured Blood Blister-like Aneurysm Treated with X-ray Angiography Perfusion(XAP)Analysis].

Two cases of ruptured blood blister-like internal carotid artery aneurysms for which low flow bypass was sufficient to attain successful treatment of trapping are reported. In the acute stage of rupture, it is troublesome to perform accurate examinations of tolerance to ischemia like balloon occlusion test(BOT)for estimating the required amount of bypass flow. In our cases, X-ray angiography perfusion(XAP)analysis was introduced, which could be performed in a couple dozen seconds without room-to-room transfer of patients, following the ordinary examination of diagnostic digital subtraction angiography. The perfusion index(PI)ratio measured in this analysis is equivalent to the laterality of cerebral blood flow between the right and left hemispheres. The PI ratio of 0.85 approximately corresponds to the mean stump pressure(MSTP)of 40mmHg, on the basis of the correlation diagram between the PI ratio and MSTP(approximate straight line:PI ratio%=0.6×MSTP+60). Even though the PI ratio of the cases was superior to this threshold of tolerance for parent artery occlusion, complementary low flow bypass was added in the acute case for the overwhelming succeeding vasospasm and for securing the flow to peripheral perforators, which resulted in a successful treatment without any ischemic events.

The influence of zoledronate and teriparatide on gamma delta T cells in mice.

BACKGROUND/PURPOSE: Few studies have investigated the possibility that bisphosphonate-related osteonecrosis of the jaw (BRONJ) might reflect an immune response; however, gamma delta T cells have been shown to significantly decline in the blood of BRONJ patients. Additionally, there have been some reports of teriparatide usage for the treatment of BRONJ. In this study, we compared the effects of zoledronate and teriparatide on lymphocyte populations and inflammatory cytokine production in mice. MATERIALS AND METHODS: Thirty female ICR mice were divided into three groups (n = 10 each): a vehicle, a zoledronate, and a teriparatide group. Drugs were administered for 8 weeks in each group. Lymphocytes in the blood and thymus were analyzed and femurs were used for histological observation and lymphocytes analysis of bone marrow. Cytokines were measured in separated serum using Milliplex® multiplex immunoassay analysis. RESULTS: Zoledronate decreased the T cell number in the bone marrow. Additionally, serum levels of interleukin (IL)-2, IL-7, IL-12, IL-15 and RANTES, which are cytokines that affect T cell activation, differentiation and/or proliferation, were significantly lower in zoledronate treated mice. Conversely, teriparatide treatment induced an increase in gamma delta T cells in peripheral blood. CONCLUSION: Gamma delta T cells in the bone marrow are expected to decrease with zoledronate treatment and increase with teriparatide treatment. If BRONJ involves a loss of gamma delta T cells in the circulation or bone marrow, then the increase in gamma delta T cells that is induced by teriparatide may account for its ability to resolve BRONJ.

Successful implantation of autologous valved conduits with self-expanding stent (stent-biovalve) within the pulmonary artery in beagle dogs.

OBJECTIVES: To evaluate the functionality of an autologous heart valve with stent (Stent-biovalve or SBV) after implantation in the pulmonic valve position in beagle dogs. ANIMALS: Five beagle dogs. METHODS: A mold with an aperture of a tri-leaflet structure was constructed from a pair of concave and convex rods to which a nitinol (NiTi) stent was mounted. This mold was embedded in a dorsal subcutaneous pouch in beagle dogs for 4 weeks. At the time of the removal, the surfaces of the molds were completely covered with connective tissues, tri-leaflet valves were formed and the NiTi stent was tightly connected to the structure. RESULTS: The mean burst strength of the SBV leaflet was 2710 mmHg (range 2280-3116 mmHg), which was approximately equal to that of the native pulmonic valve leaflet. After implantation in the pulmonary position, the SBV showed good functionality as a pulmonic valve. At 84 days after implantation, the SBV was replaced with autologous fibroblasts and collagenous tissues, and showed organization similar to that of native heart valves. CONCLUSION: Stent-Biovalves achieved good valvular function with laminar flow in the pulmonic valve position of beagle dogs.

In situ observation and enhancement of leaflet tissue formation in bioprosthetic "biovalve".

Biovalves, autologous tri-leaflet valved conduits, are formed in the subcutaneous spaces of animals. The valves are formed using molds encapsulated with autologous connective tissues. However, tissue migration into the small apertures in the molds for leaflet formation is generally slower than that for conduit formation around the molds. In this study, the formation of the leaflet tissues was directly and non-invasively observed using a wireless capsule endoscope. The molds were assembled from 6 parts, one of which was impregnated with the endoscope, and embedded into subcutaneous pouches in goats (n = 30). Tissue ingrowth into the apertures gradually occurred from the edges of the leaflet parts. Tissue formation was accompanied by capillary formation. At 63.1 ± 17.1 days after embedding, the apertures were completely replaced with autologous connective tissue, forming the leaflet tissues. Leaflet formation was enhanced by including fat tissue (46.7 ± 4.2 days) or blood (41.1 ± 6.9 days) in the apertures before embedding. The creation of slit openings, in conjunction with addition of blood to the apertures, further enhanced leaflet formation (37.0 ± 2.8 days). Since leaflet formation could be observed endoscopically, the appropriate embedding period for complete biovalve formation could be determined.

In-body tissue-engineered aortic valve (Biovalve type VII) architecture based on 3D printer molding.

In-body tissue architecture--a novel and practical regeneration medicine technology--can be used to prepare a completely autologous heart valve, based on the shape of a mold. In this study, a three-dimensional (3D) printer was used to produce the molds. A 3D printer can easily reproduce the 3D-shape and size of native heart valves within several processing hours. For a tri-leaflet, valved conduit with a sinus of Valsalva (Biovalve type VII), the mold was assembled using two conduit parts and three sinus parts produced by the 3D printer. Biovalves were generated from completely autologous connective tissue, containing collagen and fibroblasts, within 2 months following the subcutaneous embedding of the molds (success rate, 27/30). In vitro evaluation, using a pulsatile circulation circuit, showed excellent valvular function with a durability of at least 10 days. Interposed between two expanded polytetrafluoroethylene grafts, the Biovalves (N = 3) were implanted in goats through an apico-aortic bypass procedure. Postoperative echocardiography showed smooth movement of the leaflets with minimal regurgitation under systemic circulation. After 1 month of implantation, smooth white leaflets were observed with minimal thrombus formation. Functional, autologous, 3D-shaped heart valves with clinical application potential were formed following in-body embedding of specially designed molds that were created within several hours by 3D printer.