Minnesota Medical Association

Biological nitrogen fixation (BNF) is the largest natural source of new nitrogen (N) that supports terrestrial productivity1,2, yet estimates of global terrestrial BNF remain highly uncertain3,4. Here we show that this uncertainty is partly because of sampling bias, asfield BNF measurements in natural terrestrial ecosystems occur where N fixers are 17 times more prevalent than their mean abundances worldwide. To correct this bias, we develop new estimates of global terrestrial BNF by upscaling field BNF measurements using spatially explicit abundances of all major biogeochemical N-fixing niches. We find that natural biomes sustain lower BNF, 65 (52-77) Tg N yr-1, than previous empirical bottom-up estimates3,4, with most BNF occurring in tropical forests and drylands. We also find high agricultural BNF in croplands and cultivated pastures, 56 (54-58) Tg N yr-1. Agricultural BNF has increased terrestrial BNF by 64% and total terrestrial N inputs from all sources by 60% over pre-industrial levels. Our results indicate that BNF may impose stronger constraints on the carbon sink in natural terrestrial biomes and represent a larger source of agricultural N than is generally considered in analyses of the global N cycle5,6, with implications for proposed safe operating limits for N use7,8.

Endovascular treatment devices require compatible guide catheters to navigate complex vessels and anatomy. The Fubuki XF Long Sheath guide catheter (Fubuki XF) was developed with a 0.090-inch internal diameter with hydrophilic coating, an atraumatic rounded tip, and enhanced trackability and support with gradual shaft transition zones. We retrospectively analyzed a prospectively maintained database of neuroendovascular patients treated using Fubuki XF at our center (July 2022─May 2023). Baseline/procedural characteristics were collected. Outcomes of interest included technical success (procedure completion with Fubuki XF without alternative guide catheter use) and peri-procedural complications. This study included 60 patients (43.3% [26/60] female; mean age: 69.6 ± 9.7) presenting with stenosis (45.0% [27/60]), unruptured aneurysms (31.7% [19/60]), ruptured aneurysm (1.7% [1/60]), arteriovenous fistula (5.0% [3/60]), arteriovenous malformation (3.3% [2/60]), chronic subdural hematoma (3.3% [2/60]), stroke/emboli (6.7% [4/60]), vasospasm (1.7% [1/60]), or carotid web (5.0% [1/60]). Fubuki XF was used to deliver endovascular treatment devices for stenting (43.3% [26/60]), flow diversion (23.3% [14/60]), embolization (11.7% [7/60]), coiling (10.0% [6/60]), balloon angioplasty (10.0% [6/60]), and mechanical thrombectomy (1.7% [1/60]). The Fubuki XF tip was placed in the internal carotid artery in 38.3% (23/60) of cases. Technical success was achieved in all cases. One V1 non-flow-limiting dissection (not related to Fubuki XF) and one failed closure occurred (1.7% [1/60] each). No iatrogenic strokes or intraprocedural ruptures occurred. We used Fubuki XF to safely and effectively deliver a variety of compatible neuroendovascular devices. Fubuki XF was stable in all cases and locations, and there were no device-related complications or dissections.

BackgroundThe Pipeline Flex embolization device with Shield technology (PED Shield) is the first flow diverter for brain aneurysm treatment approved in the United States using surface-modified technology. The effect of PED Shield on decreasing perioperative diffusion-weighted imaging positive (DWI+) hits, as a marker for in-human decrease thrombogenicity, is unclear.ObjectiveTo determine if the number of periprocedural DWI+ lesions differs between patients with an aneurysm treated with PED Flex and PED Shield.MethodsThis retrospective study compares the outcomes of consecutive patients with an aneurysm treated with PED Flex and PED Shield. The primary outcome of interest was the occurrence of DWI+ lesions. We also assessed potential predictors of DWI+ lesions and compared the outcomes between on-label and off-label treatment indications.Results89 patients were included, 48 (54%) treated with PED Flex and 41 (46%) with PED Shield. After matching, the incidence of DWI+ lesions was 61% and 62% for the PED Flex and PED Shield groups, respectively. Results were consistent across each model with no significant differences in DWI+ lesions between treatment groups, and effect sizes ranging from OR=1.08 (95% CI 0.41 to 2.89) after propensity score matching to OR=1.84 (95% CI 0.65 to 5.47) after multivariable regression. Multivariable models demonstrated reduced DWI+ lesions with balloon-assisted therapies and posterior circulation treatment, while a significant linear relationship was encountered with fluoroscopy time.ConclusionThere was no significant difference in the incidence of perioperative DWI+ lesions between patients with an aneurysm treated with PED Flex and PED Shield. Larger cohorts are likely needed to demonstrate differences between the devices.

Interventions to address social drivers of health (SDH), such as food insecurity, transportation, and housing, can reduce future health care costs but require up-front investment. Although Medicaid managed care organizations have incentives to reduce costs, volatile enrollment patterns and coverage changes may prevent them from realizing the full benefits of their SDH investments. This phenomenon results in the "wrong-pocket problem," in which managed care organizations underinvest in SDH interventions because they cannot capture the full benefit. We propose a financial innovation, an SDH bond, to increase investments in SDH interventions. Issued by multiple managed care organizations in a Medicaid coverage region, the bond would raise immediate funds for SDH interventions that are coordinated across the organizations and delivered to all enrollees of the region. As the benefits of SDH interventions accrue and cost savings are realized, the amount managed care organizations must pay back to bond holders adjusts according to enrollment, addressing the wrong-pocket problem.

Objective:To compare technical, clinical, and safety outcomes among hip fracture patients treated with procedures supplemented by general anesthesia (GA) or spinal/regional anesthesia (S/R).Data sources:We searched for original studies on PubMed, Ovid MEDLINE, Ovid Embase, and Cochrane databases.Study selection:Studies that reported clinical outcomes in patients that underwent hip fracture surgery, had available data on type of anesthesia administered, and clinical follow-up data were selected for data extraction.Data extraction:The primary outcomes of interest were odds of mortality, including in-hospital, 30-day, 90-day, and 1-year mortality. Various adverse events (AEs) were also compared.Data synthesis:Twenty-eight studies met our selection criteria, including 190,394 patients. A total of 107,314 (56.4%) patients were treated with procedures involving GA while 83,080 (43.6%) were treated with procedures involving S/R. There was no difference in 30-day or >1-year mortality rates between the GA and SR groups; however, compared to S/R group, the GA group had a significantly higher odds of in-hospital (P = .004) and 90-day mortality (P = .004). There was no difference in odds of adverse events between the GA and the S/R group.Conclusions:Patients administered S/R for hip fracture procedures demonstrate lower risk of in-hospital mortality and 90-day mortality compared to patients administered GA.Level of evidence:Therapeutic level III.

BackgroundInitial technical constraints on the treatment of aneurysms in small parent vessels using flow diverters included challenges in navigating the delivery system and catheter size compatibility, as well as unavailability of smaller devices. The Silk Vista Baby (SVB, BALT) is a first-in-class flow-diverter device delivered using a 0.017’ microcatheter, designed for the treatment of intracranial aneurysms, including those in small diameter vessels. A systematic literature review (SLR) of the literature was performed to evaluate the safety and efficacy of using SVB to treat intracranial aneurysms in vessels less than 3.5 mm in diameter.MethodsWe performed a PRISMA-compliant SLR to evaluate the outcomes of SVB in the treatment of aneurysms in small intracranial vessels. Primary outcomes were occlusion status and major stroke, and secondary outcomes included all-cause mortality, procedure-related neurologic death, and post-operative aneurysm rupture. Data were expressed as descriptive statistics only.ResultsA total of four studies, including 163 patients with 173 intracranial aneurysms, were included. The most common aneurysm locations were the anterior cerebral artery (24.9% [43/173]), the middle cerebral artery (24.3% [42/173]), and the anterior communicating artery (23.1% [40/173]). Parent artery diameter ranged from 0.9 mm to 3.6 mm, most aneurysms were saccular (81.8%), and 29% were acutely or previously ruptured. Overall, 32.9% (57/173) of the aneurysms managed with the SVB had previously been treated, mainly using coiling. Moreover, adjunct coiling use ranged from 2.1% to 30.2%. Technical success was obtained in 98.8% of cases. Overall, complete and adequate (complete and near-complete) aneurysm occlusion were 60.6% and 72.1%, respectively, on studies with available early-term follow-up (mean ≥6 months). Postoperative bleeding rate across the studies was 1.8%, all case occurring previously or acutely ruptured aneurysms. Major stroke was noted in 1.2% of cases, and branch occlusion or stent thrombus formation in 5.5%. Mortality rate among the studies was 2.5%, with 3 instances adjudicated as neurologic deaths (1.8%).ConclusionThis systematic review suggests that SVB is a safe and effective treatment for intracranial aneurysms in small vessels. Device trackability and reduced system dimensions, also facilitated the treatment of previously judged not amenable lesions, including a wide range of aneurysms located in anterior and posterior circulation distal vessels. Further prospective and comparative studies with patient outcome data specific to aneurysm location are needed to confirm the safety and efficacy of SVB.DisclosuresR. Hanel: 1; C; Unrestricted research grant from NIH, Interline Endowment, Microvention, Stryker, CNX.. 2; C; Medtronic, Stryker, Cerenovous, Microvention, Balt, Phenox, Rapid Medical, and Q’Apel. He is on advisory board for MiVI, eLum, Three Rivers, Shape Medical and Corindus.. 4; C; InNeuroCo, Cerebrotech, eLum, Endostream, Three Rivers Medical Inc, Scientia, RisT, BlinkTBI, and Corindus.. G. Cortez: None. V. Benalia: None. E. Sheffels: None. D. Sutphin: None. J. Pederson: None. V. Pereira: None.