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Journal of Vascular Surgery Jun 2024The recent publication of randomized trials comparing open bypass surgery to endovascular therapy in chronic limb threatening ischemia (CLTI) patients, BEST-CLI and...
OBJECTIVE
The recent publication of randomized trials comparing open bypass surgery to endovascular therapy in chronic limb threatening ischemia (CLTI) patients, BEST-CLI and BASIL-2, has resulted in potentially contradictory findings. The trials differed significantly with respect to anatomic disease patterns and primary endpoints. We performed an analysis of BEST-CLI patients with significant infrapopliteal disease undergoing open tibial bypass or endovascular tibial interventions to formulate a relevant comparator to the outcomes reported from BASIL-2.
METHODS
The study population consisted of BEST-CLI patients with adequate single segment saphenous vein conduit randomized to open bypass or endovascular intervention (Cohort 1) who additionally had significant infrapopliteal disease and underwent tibial level intervention. The primary outcome was major adverse limb event (MALE) or all-cause death. MALE included any major limb amputation or major re-intervention. Outcomes were evaluated using Cox proportional regression models.
RESULTS
The analyzed subgroup included a total of 665 patients with 326 in the open tibial bypass group and 339 in the tibial endovascular intervention group. The primary outcome of MALE or all cause death at 3 years was significantly lower in the surgical group at 48.5% compared to 56.7% in the endovascular group (p=0.0018). Mortality was similar between groups (35.5% open vs. 35.8% endovascular; p=0.94 whereas MALE events were lower in the surgical group (23.3% vs. 35.0%; p<0.0001). This included a lower rate of major reinterventions in the surgical group (10.9%) compared to the endovascular group (20.2%; p=0.0006). Freedom from above ankle amputation or all-cause death was similar between treatment arms at 43.6% in the surgical group compared to 45.3% the endovascular group (p=0.30) however there were fewer above ankle amputations in the surgical group (13.5%) compared to the endovascular group (19.3%; p=0.0205). Perioperative (30-day) death was similar between treatment groups (2.5% open vs 2.4% endovascular; p=0.93) as was 30-day MACE (5.3% open vs 2.7% endovascular; p=0.12).
CONCLUSIONS
Among patients with suitable single segment great saphenous vein who underwent infrapopliteal revascularization for CLTI, open bypass surgery was associated with a lower incidence of MALE or death and less major amputation compared to endovascular intervention. Amputation free survival was similar between the groups. Further investigations into differences in comorbidities, anatomic extent, and lesion complexity are needed to explain differences between the BEST-CLI and BASIL-2 reported outcomes.
PubMed: 38908805
DOI: 10.1016/j.jvs.2024.05.049 -
Journal of Vascular Surgery Jun 2024The Human Acellular Vessel (HAV) is a novel, off-the-shelf biologic conduit being evaluated for arterial reconstructions. Regulatory studies in peripheral arterial...
OBJECTIVE
The Human Acellular Vessel (HAV) is a novel, off-the-shelf biologic conduit being evaluated for arterial reconstructions. Regulatory studies in peripheral arterial disease (PAD) to date have consisted of single-arm cohorts with no comparator groups to contrast performance against established standards. This study aimed to compare outcomes of the HAV with autologous great saphenous vein (GSV) in patients with advanced PAD undergoing infrageniculate bypass.
METHODS
Patients with advanced PAD and no autologous conduit who underwent bypass with the 6-mm diameter HAV (Group 1; n = 34) (March 2021-February 2024) were compared with a multicenter historical cohort who had bypass with single-segment GSV (group 2; n = 88) (January 2017-December 2022). The HAV was used under an Investigational New Drug protocol issued by the Food and Drug Administration (FDA) under the agency's Expanded Access Program.
RESULTS
Demographics were comparable between groups (mean age 69 ± 10 years; 71% male). Group 1 had higher rates of tobacco use (37 pack-years vs 28 pack-years; P = .059), coronary artery disease (71% vs 43%; P = .007), and prior coronary artery bypass grafting (38% vs 14%; P = .003). Group 1 had more patients classified as wound, ischemia, and foot infection clinical stage 4 (56% vs 33%; P = .018) and with previous index leg revascularizations (97% vs 53%; P < .001). Both groups had a similar number of patients with chronic limb-threatening ischemia (Rutherford class 4-6) (88% vs 86%; P = .693) and Global Anatomic Staging System stage III (91% vs 96%; P = .346). Group 1 required a composite conduit (two HAV sewn together) in 85% of bypasses. The tibial vessels were the target in 79% of group 1 and 100% of group 2 (P < .001). Group 1 had a lower mean operative time (364 minutes vs 464 minutes; P < .001). At a median of 12 months, major amputation-free survival (73% vs 81%; P = .55) and overall survival (84% vs 88%; P = .20) were comparable. Group 1 had lower rates of primary patency (36% vs 50%; P = .044), primary-assisted patency (45% vs 72%; P = .002), and secondary patency (64% vs 72%; P = .003) compared with group 2.
CONCLUSIONS
Implanted under Food and Drug Administration Expanded Access provisions, the HAV was more likely to be used in redo operations and cases with more advanced limb ischemia than GSV. Despite modest primary patency, the HAV demonstrated resilience in a complex cohort with no autologous conduit options, achieving good secondary patency and providing major amputation-free survival comparable with GSV at 12 months.
PubMed: 38904582
DOI: 10.1016/j.jvs.2024.05.012 -
Compendium of Continuing Education in... Jun 2024The anatomic proximity of maxillary posterior teeth to the maxillary sinus provides a natural conduit for the spread of dental pathology into the maxillary sinus. This... (Review)
Review
The anatomic proximity of maxillary posterior teeth to the maxillary sinus provides a natural conduit for the spread of dental pathology into the maxillary sinus. This diffusion results in the development of sinus disease attributable to endodontic pathology, and is termed "maxillary sinusitis of endodontic origin" (MSEO). Ultimately, suspicion of odontogenic causes of sinus disease should come as a relief to the provider and patient alike as the conditions are very treatable by noninvasive means with high expected success. This article reviews the diagnosis and management of odontogenic sinusitis with an emphasis on CBCT imaging as part of the interdisciplinary diagnostic workup. Illustrative cases documenting the treatment of MSEO are also presented.
Topics: Humans; Maxillary Sinusitis; Cone-Beam Computed Tomography
PubMed: 38900445
DOI: No ID Found -
Vascular Jun 2024The 2019 Global Vascular Guidelines recommended open bypass for patients at average risk with greater limb severity and anatomical complexity. However, the outcomes of...
OBJECTIVES
The 2019 Global Vascular Guidelines recommended open bypass for patients at average risk with greater limb severity and anatomical complexity. However, the outcomes of tibial and pedal bypass (TPB) are inferior to those of above-the-knee surgical revascularization. This may be due to the technical difficulty and need for development of skills to perform TPB. However, there is a limited knowledge on the learning curve in TPB. Thus, the aim of the study is to assess this learning curve in a single-center retrospective analysis.
METHODS
Cases treated with TPB with an autologous vein conduit in patients with chronic limb-threatening ischemia (CLTI) at a Japanese single center from 2009 to 2022 were analyzed retrospectively. The primary endpoint was the learning curve for TPB.
RESULTS
The study included 449 TPB procedures conducted by a single main surgeon in patients with CLTI (median age, 75 years; 309 males; diabetes mellitus, 73%; end stage renal failure with hemodialysis, 44%). The operative time decreased significantly as the number of cases accumulated ( < .001). Using the cumulative sum (CUSUM) operative time, the learning curve was estimated to be phase 1 (initial learning curve) for 134 cases (1-134); phase 2 (competent period) for 179 cases (135-313); and phase 3 (mastery and challenging period) for 136 cases (314-449). The mean follow-up period was 34 ± 31 months. The 1- and 3-year limb salvage rates of 97% and 96% in phase 3 were significantly higher than those in phases 1 and 2 ( < .001, = .029). Major adverse limb events (MALE) occurred in 117 (26%) patients, and the 1- and 3-year MALE rates of 10% and 17% in phase 3 were significantly lower than those in phases 1 and 2 ( < .001, = .009).
CONCLUSIONS
In the study, vascular surgeon required a learning curve of 134 TPB cases to Overcoming the learning curve for bypass was associated with improvement of medium-term outcomes for limb salvage and freedom from MALE.
PubMed: 38896848
DOI: 10.1177/17085381241263909 -
Nature Reviews. Cancer Jun 2024The leptomeninges, the cerebrospinal-fluid-filled tissues surrounding the central nervous system, play host to various pathologies including infection, neuroinflammation... (Review)
Review
The leptomeninges, the cerebrospinal-fluid-filled tissues surrounding the central nervous system, play host to various pathologies including infection, neuroinflammation and malignancy. Spread of systemic cancer into this space, termed leptomeningeal metastasis, occurs in 5-10% of patients with solid tumours and portends a bleak clinical prognosis. Previous, predominantly descriptive, clinical studies have provided few insights. Recent development of preclinical leptomeningeal metastasis models, alongside genomic, transcriptomic and proteomic sequencing efforts, has provided groundwork for mechanistic understanding and identification of long-needed therapeutic targets. Although previously understood as an anatomically isolated compartment, the leptomeninges are increasingly appreciated as a major conduit of communication between the systemic circulation and the central nervous system. Despite the unique nature of the leptomeningeal microenvironment, the general principles of metastasis hold true: cells metastasizing to the leptomeninges must gain access to the new environment, survive within the space and evade the immune system. The study of leptomeningeal metastasis has the potential to uncover novel site-specific metastatic principles and illuminate the physiology of the leptomeningeal space. In this Review, we provide a biology-focused overview of how metastatic cells reach the leptomeninges, thrive in this nutritionally sparse environment and evade the detection of the omnipresent immune system.
PubMed: 38871881
DOI: 10.1038/s41568-024-00700-y -
Journal of Endovascular Therapy : An... Jun 2024Thoracic endovascular aortic repair (TEVAR), originally conceived for deployment distal to the left subclavian artery (LSA), has been recently extended to more proximal...
PURPOSE
Thoracic endovascular aortic repair (TEVAR), originally conceived for deployment distal to the left subclavian artery (LSA), has been recently extended to more proximal landing zones. Among total endovascular solutions, the "Canaud technique" for Physician-Modified Thoracic Endovascular Grafts (C-PMEGs) has gained acceptance with good early results. The aim of this study is to report the proportion of patients with zone 0, 1, and 2 aortic arch lesions that could theoretically be treated with a C-PMEG.
MATERIALS AND METHODS
Computed tomography angiography (CTA) of all consecutive patient candidates to open, hybrid, or endovascular arch repair from January 2009 to July 2023 at our Institution were analyzed. The assessment of feasibility of C-PEMG was conducted following previously extensively described anatomical criteria.
RESULTS
During the study period, 209 consecutive patients were candidates for an open, hybrid, or endovascular aortic arch repair. Of them, 164 patients had a preoperative CTA scan eligible for analysis. One hundred twenty-six patients were male (76.8 %), with a mean age of 67 ± 10.8 years. Ninety-four patients (57.3%) were affected by atherosclerotic aneurysms, 48 post-dissecting aneurysms (29.3%) and 22 penetrating aortic ulcers (PAUs) (13.4%). Twenty patients (12.2%) were suitable for double-fenestrated C-PMEG, and 34 patients (20.7%) for single-fenestrated C-PMEG, totaling 32.9% of the entire cohort. The combination of supra-aortic trunks (SAT) bypass or the use of covered stent in IA or left common carotid artery (LCCA) as adjunctive maneuvers, would extend the C-PMEGs feasibility to 69 patients (42.1%). The use of an iliac graft conduit in 3 (1.8%) patients with inadequate ileo-femoral accesses would increase the C-PMEG suitability to 72 patients (43.9%). The main reason for exclusion was excessive ascending aortic diameter in 78 patients (47.6%).
CONCLUSIONS
The use of C-PMEG was shown to be theoretically feasible in a percentage of patients ranging from 32.9 to 43.9% affected by aortic arch aneurysms, dissections, and PAU. The main reason for exclusion was the dimension of the ascending aorta. The C-PMEG technique is a viable option in aortic arch lesions endovascular treatment. An off-the-shelf device with similar characteristics could also be used in emergency, avoiding the limitations of physician modifications (such as time for back-table procedure, sterility, off-label use).
CLINICAL IMPACT
Thoracic endovascular aortic repair (TEVAR) has been extended to more proximal landing zones for the treatment of aortic arch aneurysm, dissections, penetrating aortic ulcers. Among total endovascular solutions, the "Canaud technique" for Physician-Modified Thoracic Endovascular Grafts (C-PMEGs) has gained acceptance with good early results. The anatomical feasibility in 164 consecutive patients was 69 patients (42.1%), with the combination of supra-aortic trunks (SAT) bypass or the use of covered stent in IA or left common carotid artery (LCCA) as adjunctive maneuvers, showing that the C-PMEG technique is a viable option in aortic arch lesions endovascular treatment.
PubMed: 38850041
DOI: 10.1177/15266028241258148 -
Annals of Vascular Surgery May 2024The heparin-bonded expanded polytetrafluoroethylene (He-ePTFE) conduit is an option for patients requiring infrainguinal revascularization (iIR), but the risk of failure...
BACKGROUND
The heparin-bonded expanded polytetrafluoroethylene (He-ePTFE) conduit is an option for patients requiring infrainguinal revascularization (iIR), but the risk of failure may be unpredictable, especially in cases with poor run-off. Intraoperative transit-time flow (TTF) provides an automated and quantitative analysis of flow and may serve as an adjunct evaluation during surgical revascularization. The aim of this study was to assess TTF in patients undergoing iIR with He-PTFE at 3 referral hospitals and to establish a predictive flow threshold for graft occlusion.
METHODS
A prospective registry initiated in 2020 enrolled patients undergoing iIR using He-PTFE for critical limb ischemia or severe claudication, and TTF measurement was analyzed. Preoperative assessments of anatomical and clinical characteristics were available for all patients. The HT353 Optima Meter (Transonic Systems Inc., Ithaca, NY, USA) was used in all procedures according to a standardized protocol. The institutional ethics committee approved the study. A predictive model using receiver operating characteristic curve analysis was utilized to establish the threshold of flow, and variables were compared. Anatomical and clinical evaluation were reported according to Rutherford grade, Global Limb Anatomic System and Wound, Ischemia, and foot Infection classification. The main outcome considered was the correlation between TTF and graft occlusion. Secondary outcomes included survival, other predictors of graft occlusion, freedom from major adverse cardiovascular events, and freedom from major amputation.
RESULTS
Among 68 patients, 55.8% had Rutherford 5-6, 45.6% had Global Limb Anatomic System 3 and 73.5% had Wound, Ischemia, and foot Infection 3-4. Distal anastomosis was at tibial level in 23.5% and mean diameter of conduit was 6.4 mm. Basal and postoperative TTF were 27.8 ± 15.6 ml/min and 109.0 ± 53.0 ml/min, respectively. After a mean follow-up of 18 ± 13 months, 7 (10.9%) patients presented graft occlusion and 5 (7.8%) required major amputation. TTF threshold = 80 ml/min revealed a sensitivity and specificity of 81.8% (95% confidence interval 48.2-97.7) and 80.7% (95% confidence interval 68.1-90.0) respectively, and it was selected as cut-off for graft occlusion. Freedom from graft occlusion in patients with TTF >80 ml/min vs. TTF ≤80 ml/min at 6, 12, and 24 months was 95.7% (standard error (SE) = 0.030) vs. 65.5% (SE = 0.115), 95.7% (SE = 0.030) vs. 58.9% (SE = 0.120) and 90.9% (SE = 0.054) vs. 51.6% (SE = 0.126), P = 0.0003. No statistical difference in primary patency, secondary patency and limb salvage was observed. At multivariate analysis, distal anastomosis at tibial vessel (odds ratio 8.50) and TTF ≤80 ml/min (odds ratio 9.39) were independent predictors of graft occlusion.
CONCLUSIONS
These results suggest that TTF may serve as a valuable tool in the management of iIR. A TTF measurement of ≤80 ml/min should be regarded as a predictor of graft occlusion, prompting consideration of additional intraoperative maneuvers to enhance arterial flow. Caution should be exercised in patients requiring direct tibial artery revascularization, as it represents a predictor of failure independent of TTF levels. Larger cohorts of patients and longer follow-up periods are necessary to confirm these findings.
PubMed: 38821469
DOI: 10.1016/j.avsg.2024.04.008 -
Oecologia May 2024The vulnerability of plant xylem to embolism can be described as the water potential at which xylem conductivity is lost by 50% (P). According to the traditional...
The vulnerability of plant xylem to embolism can be described as the water potential at which xylem conductivity is lost by 50% (P). According to the traditional hypothesis of hydraulic vulnerability segmentation, the difference in vulnerability to embolism between branches and roots is positive (P > 0). It is not clear whether this occurs broadly across species or how segmentation might vary across aridity gradients. We compiled hydraulic and anatomical datasets from branches and roots across 104 woody species (including new measurements from 10 species) in four biomes to investigate the relationships between P and environmental factors associated with aridity. We found a positive P relationship across species, and evidence that P increases with aridity. Branch xylem hydraulic conductivity transitioned from more efficient (e.g., wider conduit, higher hydraulic conductivity) to safer (e.g., narrower conduit, more negative P) in response to the increase of aridity, while root xylem hydraulic conductivity remained unchanged across aridity gradients. Our results demonstrate that the hydraulic vulnerability difference between branches and roots is more positive in species from arid regions, largely driven by modifications to branch traits.
Topics: Plant Roots; Xylem; Water
PubMed: 38772916
DOI: 10.1007/s00442-024-05562-7 -
European Journal of Mechanics. B, Fluids 2024This study aims at clarifying the relation between the oscillatory flow of cerebrospinal fluid (CSF) in the cerebral aqueduct, a narrow conduit connecting the third and...
This study aims at clarifying the relation between the oscillatory flow of cerebrospinal fluid (CSF) in the cerebral aqueduct, a narrow conduit connecting the third and fourth ventricles, and the corresponding interventricular pressure difference. Dimensional analysis is used in designing an anatomically correct scaled model of the aqueduct flow, with physical similarity maintained by adjusting the flow frequency and the properties of the working fluid. The time-varying pressure difference across the aqueduct corresponding to a given oscillatory flow rate is measured in parametric ranges covering the range of flow conditions commonly encountered in healthy subjects. Parametric dependences are delineated for the time-averaged pressure fluctuations and for the phase lag between the transaqueductal pressure difference and the flow rate, both having clinical relevance. The results are validated through comparisons with predictions obtained with a previously derived computational model. The parametric quantification in this study enables the derivation of a simple formula for the relation between the transaqueductal pressure and the stroke volume. This relationship can be useful in the quantification of transmantle pressure differences based on non-invasive magnetic-resonance-velocimetry measurements of aqueduct flow for investigation of CSF-related disorders.
PubMed: 38770034
DOI: 10.1016/j.euromechflu.2024.01.010 -
JACC. Case Reports May 2024Fontan pathway obstruction is a potentially serious complication characterized by an anatomical or functional narrowing anywhere in the cavo-pulmonary pathways. Here, we...
Fontan pathway obstruction is a potentially serious complication characterized by an anatomical or functional narrowing anywhere in the cavo-pulmonary pathways. Here, we report the first case in the literature where an innovative Fontan conduit rehabilitation procedure with intravascular lithotripsy was used achieving a dramatic increase in the pathway size.
PubMed: 38708431
DOI: 10.1016/j.jaccas.2024.102296