Left ventricular CRT-D lead implantation using the retrograde approach following lateral vein balloon angioplasty

A 60-year-old female with heart failure with reduced left ventricle ejection fraction, implantable cardiac defibrillator and left bundle branch block was admitted to Department of Cardiology for cardiac resynchronization therapy defibrillator upgrade. Due to difficulties with advancement of left ventricular lead to lateral coronary vein, balloon angioplasty with use of retrograde approach via collateral branches and two CS sheaths positioning was performed. Final position of lead in lateral vein was achieved resulting with pacing threshold of 0.7 V/0.5 ms, impedance of 720 Ω and QRS of 130 ms.

Monosynaptic Rabies Tracing Reveals Sex- and Age-Dependent Dorsal Subiculum Connectivity Alterations in an Alzheimer's Disease Mouse Model

The subiculum (SUB), a hippocampal formation structure, is among the earliest brain regions impacted in Alzheimer's disease (AD). Toward a better understanding of AD circuit-based mechanisms, we mapped synaptic circuit inputs to dorsal SUB using monosynaptic rabies tracing in the 5xFAD mouse model by quantitatively comparing the circuit connectivity of SUB excitatory neurons in age-matched controls and 5xFAD mice at different ages for both sexes. Input-mapped brain regions include the hippocampal subregions (CA1, CA2, CA3), medial septum and diagonal band, retrosplenial cortex, SUB, postsubiculum (postSUB), visual cortex, auditory cortex, somatosensory cortex, entorhinal cortex, thalamus, perirhinal cortex (Prh), ectorhinal cortex, and temporal association cortex. We find sex- and age-dependent changes in connectivity strengths and patterns of SUB presynaptic inputs from hippocampal subregions and other brain regions in 5xFAD mice compared with control mice. Significant sex differences for SUB inputs are found in 5xFAD mice for CA1, CA2, CA3, postSUB, Prh, lateral entorhinal cortex, and medial entorhinal cortex: all of these areas are critical for learning and memory. Notably, we find significant changes at different ages for visual cortical inputs to SUB. While the visual function is not ordinarily considered defective in AD, these specific connectivity changes reflect that altered visual circuitry contributes to learning and memory deficits. Our work provides new insights into SUB-directed neural circuit mechanisms during AD progression and supports the idea that neural circuit disruptions are a prominent feature of AD.

Long-term Patency of Retrograde Bypass Using a Distal Stump of the Parietal Superficial Temporal Artery for Moyamoya Disease

There have been a number of anastomosis methods of bypass techniques reported for moyamoya disease. However, there are yet no randomized controlled trials conducted on the anastomosis method. Retrograde blood flow of the superficial temporal artery (STA) may be used as one of the donor options. Here, we examined the tolerability of retrograde bypass using a distal stump of the parietal STA (dsPSTA). Anastomosis between the dsPSTA and middle cerebral artery (MCA) was performed for consecutive patients with moyamoya disease whose parietal STA was visualized to be longer than 10 cm using contrast-enhanced computed tomography preoperatively. Retrospectively, we have examined its patency and clinical outcome. Retrograde dsPSTA-MCA bypass was performed in 22 hemispheres of 17 patients. The patency of retrograde dsPSTA-MCA bypass in all 22 anastomoses could be confirmed during follow-up periods (mean: 5.5, range: 2-15 years). No recurrence of ischemic events was observed. The dsPSTA-MCA bypass using retrograde blood flow has been determined as one of the many promising anastomosis methods, and long-term patency was achieved in moyamoya disease.

Cytoarchitectonic and connection stripes in the dysgranular insular cortex in the macaque monkey

The insula has been classically divided into broad granular, dysgranular, and agranular architectonic sectors. We previously proposed a novel partition, dividing each sector into four to seven sharply delimited architectonic areas, with the dysgranular areas being possibly further subdivided into subtle horizontal partitions or "stripes." In architectonics, discrete subparcellations are prone to subjective variability and need being supported with additional neuroanatomical methods. Here, using a secondary analysis of indirect connectional data in the rhesus macaque monkey, we examined the spatial relationship between the dysgranular architectonic stripes and tract-tracing labeling patterns produced in the insula with injections of neuronal tracers in other cortical regions. The injections consistently produced sharply delimited patches of anterograde and/or retrograde labeling, which formed stripes across consecutive coronal sections of the insula. While the overall pattern of labeling on individual coronal sections varied with the injection site, the boundaries of the patches consistently coincided with architectonic boundaries on an adjacent cyto- (Nissl) and/or myelo- (Gallyas) architectonic section. This overlap supports the existence of a fine dysgranular stripe-like partition of the primate insula, with possibly major implications for interoceptive processing in primates including humans. The modular organization of the insula could underlie a serial stream of integration from a dorsal primary interoceptive cortex toward progressively more ventral egocentric "self-agency" and allocentric "social" dysgranular processing units.

The clinical features and treatment of fishhook injuries in freshwater turtles: 126 cases from 1997-2022

OBJECTIVE

To describe the clinical features, treatment, and outcomes of wild freshwater turtles with fishing hook injuries.

ANIMALS

126 wild turtles residing in central North Carolina that were presented to a wildlife rescue clinic.

METHODS

Medical records from July 1997 to July 2022 were reviewed, and data were collected and analyzed.

RESULTS

The most common species presenting for a fishhook injury was the yellow-bellied slider (Trachemys scripta scripta) (n = 69/126 [54.8%]; 95% CI, 45.7 to 63.6). The most common location identified was the oral cavity (n = 77/140 [55%]; 95% CI, 46.4 to 63.4) and the most common removal method was retrograde removal after cutting the barb off of the hook (76/120 [63.3%]; 95% CI, 54.1 to 71.9). Fishhooks embedded in the esophagus had a significantly higher chance of complications affecting recovery (OR estimate, 3.49; 95% CI, 1.07 to 11.38). There was no significant increase in mortality associated with the location of the injury; however, there was a significant increase in mortality in patients that experienced complications (P < 0.001). The time in care ranged from 1 to 150 days (median, 16 days). Of the turtles evaluated, 10.8% (n = 12/111; 95% CI, 5.7 to 18.1) were euthanized or died after treatment and 89.2% (99/111; 95% CI, 81.9 to 94.3) were released.

CLINICAL RELEVANCE

These findings describe various successful techniques to remove fishhooks from turtles. While no superior treatment was identified, considerations should be taken to provide patient comfort, decrease injury-associated complications, and shorten recovery time by using minimally invasive techniques. Overall, freshwater turtles with fishhook injuries have a high release rate even when the injuries are severe.

The Retrograde Approach to Chronic Total Occlusion Percutaneous Coronary Interventions: Technical Analysis and Procedural Outcomes

BACKGROUND

Retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with lower success and higher complication rates when compared with the antegrade approach.

OBJECTIVES

This study sought to assess contemporary techniques and outcomes of retrograde CTO PCI.

METHODS

We examined the baseline characteristics, procedural techniques and outcomes of 4,058 retrograde CTO PCIs performed at 44 centers between 2012 and 2023. Major adverse cardiac events (MACE) included any of the following in-hospital events: death, myocardial infarction, repeat target vessel revascularization, pericardiocentesis, cardiac surgery, and stroke.

RESULTS

The average J-CTO (Multicenter CTO Registry in Japan) score was 3.1 ± 1.1. Retrograde crossing was successful in 60.5% and lesion crossing in 81.6% of cases. The collaterals pathways successfully used were septals in 62.0%, saphenous vein grafts in 17.4%, and epicardials in 19.1%. The technical and procedural success rates were 78.7% and 76.6%, respectively. When retrograde crossing failed, technical success was achieved in 50.3% of cases using the antegrade approach. In-hospital MACE was 3.5%. The clinical coronary perforation rate was 5.8%. The incidence of in-hospital MACE with retrograde true lumen crossing, just marker antegrade crossing, conventional reverse controlled antegrade and retrograde tracking (CART), contemporary reverse CART, extended reverse CART, guide-extension reverse CART, and CART was 2.1%, 0.8%, 5.5%, 3.0%, 2.1%, 3.2%, and 4.1%, respectively; P = 0.01).

CONCLUSIONS

Retrograde CTO PCI is utilized in highly complex cases and yields moderate success rates with 5.8% perforation and 3.5% periprocedural MACE rates. Among retrograde crossing strategies, retrograde true lumen puncture was the safest. There is need for improvement of the efficacy and safety of retrograde CTO PCI.

Collateral grading systems in retrograde percutaneous coronary intervention of chronic total occlusions

BACKGROUND

The Japanese Channel (J-Channel) score was introduced to aid in retrograde percutaneous coronary intervention (PCI) of chronic total coronary occlusions (CTOs). The predictive value of the J-Channel score has not been compared with established collateral grading systems such as the Rentrop classification and Werner grade.

AIMS

To investigate the predictive value of the J-Channel score, Rentrop classification and Werner grade for successful collateral channel (CC) guidewire crossing and technical CTO PCI success.

METHODS

A total of 600 prospectively recruited patients underwent CTO PCI. All grading systems were assessed under dual catheter injection. CC guidewire crossing was considered successful if the guidewire reached the distal segment of the CTO vessel through a retrograde approach. Technical CTO PCI success was defined as thrombolysis in myocardial infarction flow grade 3 and residual stenosis <30%.

RESULTS

Of 600 patients, 257 (43%) underwent CTO PCI through a retrograde approach. Successful CC guidewire crossing was achieved in 208 (81%) patients. The predictive value of the J-Channel score for CC guidewire crossing (area under curve 0.743) was comparable with the Rentrop classification (0.699, p = 0.094) and superior to the Werner grade (0.663, p = 0.002). Technical CTO PCI success was reported in 232 (90%) patients. The Rentrop classification exhibited a numerically higher discriminatory ability (0.676) compared to the J-Channel score (0.664) and Werner grade (0.589).

CONCLUSIONS

The J-channel score might aid in strategic collateral channel selection during retrograde CTO PCI. However, the J-Channel score, Rentrop classification, and Werner grade have limited value in predicting technical CTO PCI success.

Retrograde Trans-Amputation Embolectomy of Common, Superficial and Deep Femoral Arteries for Inflow Revascularisation During Above-Knee Amputation: A Case Report and Review of the Literature

BACKGROUND

Primary above-knee amputation (AKA) may at times be the only option for unsalvageable acute lower limb ischemia. However, occlusion of the femoral arteries may result in poor inflow and contribute to wound complications such as stump gangrene and sepsis. Previously attempted inflow revascularisation techniques include surgical bypass and percutaneous angioplasty and/or stenting.

CASE PRESENTATION

We present a case of a 77-year-old lady with unsalvageable acute right lower limb ischemia secondary to cardioembolic occlusion of the common (CFA), superficial (SFA) and deep (PFA) femoral arteries. We performed a primary AKA with inflow revascularisation using a novel surgical technique involving endovascular retrograde embolectomy of the CFA, SFA and PFA via the SFA stump. The patient made an uneventful recovery without any wound complications. Detailed description of the procedure is followed by a discussion of the literature on inflow revascularisation in the treatment and prevention of stump ischemia.

Case report: Retrograde endovascular recanalization of vertebral artery occlusion with non-tapered stump via the deep cervical collateral

Introduction

Vertebral artery (VA) occlusive disease is the major cause of posterior circulation ischemic stroke. Endovascular recanalization has been reported as a feasible treatment for patients with symptomatic VA occlusion refractory to optimal medical therapy. However, VA occlusion with non-tapered stump exhibits a low technique success rate when treated by antegrade endovascular therapy because of increased difficulty in passing the guidewire into the occluded segment. Herein, we presented a novel endovascular approach to recanalize chronically occluded VA with a non-tapered stump using a retrograde method via the deep cervical collateral, which has not been reported before.

Case presentation

The present case was a patient with VA ostial occlusion with non-tapered stump and distal severe stenosis of the left VA who had recurrent posterior circulation transit ischemic attacks under optimal medical therapy. CT angiography demonstrated proximal non-tapered occlusion and distal severe stenosis of the left VA, and that the right VA did not converge with the left VA into basilar artery. Endovascular treatment was recommended and performed on this patient. However, antegrade endovascular recanalization of the left VA origin occlusion failed because the micro guidewire was unable to traverse the occluded segment. Fortunately, robust collateral from the deep cervical artery to the V3 segment of the left VA developed, in which we advanced the micro guidewire to the V3 segment of the left VA and reversely passed the micro guidewire through the occluded segment. Then, the occlusion and stenosis of the left VA were successfully resolved with angioplasty and stenting. After the procedure, the patient reported no neurological symptoms under medical therapy during 3-month follow-up.

Conclusion

Antegrade endovascular recanalization of VA occlusion with a non-tapered stump is a challenge. The retrograde endovascular method via the cervical collateral may be an alternative for this type of VA occlusion, which requires further exploration.

Incidence, Predictors, and Strategies for Retrograde Wire Tracking Failure via Poor Septal Collateral Channels in Chronic Total Occlusion

Background

Retrograde guidewire (GW) tracking success via a poor septal collateral channel (CC) when an antegrade approach fails is crucial for successful revascularization of coronary chronic total occlusion (CTO) with poor septal CC. However, the incidence, predictors, and management strategies for retrograde GW tracking failure via poor septal CC remain unclear.

Methods

In total, 122 CTO patients who underwent retrograde septal percutaneous coronary intervention (PCI) with poor CC between January 2017 and May 2022 were retrospectively analyzed. Patients were divided into the retrograde GW tracking success group (success group) and the retrograde GW tracking failure group (failure group). Clinical and angiographic data were compared to investigate the predictors of retrograde GW tracking failure.

Results

The incidence of GW tracking failure was 22.1% (27/122). Patients in the failure group had a higher prevalence of left anterior descending artery (LAD) CTO (66.7% vs 37.9%; p = 0.009) and a higher incidence of well-developed non-septal collateral (66.7% vs 30.5%; p = 0.001). Patients with a septal CC diameter ≥ 1 mm (48.1% vs 70.5%; p = 0.040), ≥ 3 septal CCs (44.4% vs 66.3%; p = 0.046), and initial retrograde application of Guidezilla (37.0% vs 60.0%; p = 0.048) were significantly lower in the failure group than in the success group. The binary logistics regression model showed that a CC diameter < 1 mm, well-developed non-septal collateral, and LAD CTO were independent predictors for GW tracking failure in patients undergoing retrograde CTO PCI via poor septal CC.

Conclusion

The success rate of retrograde GW tracking via poor septal CC was high, with a relatively high procedural success rate. A CC diameter < 1 mm, well-developed non-septal collateral, and LAD CTO were independent predictors of GW tracking failure in patients undergoing retrograde CTO PCI via poor septal CC.

Recruitment of Hippocampal and Thalamic Pathways to the Central Amygdala in the Control of Feeding Behavior Under Novelty

It is adaptive to restrict eating under uncertainty, such as during habituation to novel foods and unfamiliar environments. However, sustained restrictive eating is a core symptom of eating disorders and has serious long-term health consequences. Current therapeutic efforts are limited, because the neural substrates of restrictive eating are poorly understood. Using a model of feeding avoidance under novelty, our recent study identified forebrain activation patterns and found evidence that the central nucleus of the amygdala (CEA) is a core integrating node. The current study analyzed the activity of CEA inputs in male and female rats to determine if specific pathways are recruited during feeding under novelty. Recruitment of direct inputs from the paraventricular nucleus of the thalamus (PVT), the infralimbic cortex (ILA), the agranular insular cortex (AI), the hippocampal ventral field CA1, and the bed nucleus of the stria terminals (BST) was assessed with combined retrograde tract tracing and Fos induction analysis. The study found that during consumption of a novel food in a novel environment, larger number of neurons within the PVTp and the CA1 that send monosynaptic inputs to the CEA were recruited compared to controls that consumed familiar food in a familiar environment. The ILA, AI, and BST inputs to the CEA were similarly recruited across conditions. There were no sex differences in activation of any of the pathways analyzed. These results suggest that the PVTp-CEA and CA1-CEA pathways underlie feeding inhibition during novelty and could be potential sites of malfunction in excessive food avoidance.

Efficiency of the Guide Extension Catheter-Facilitated Tip-in Technique in the Recanalization of Coronary Chronic Total Occlusion

Background

The tip-in technique, which involves advancing an antegrade microcatheter cross the lesion over a retrograde guidewire, is an elaborated maneuver in the recanalization of coronary chronic total occlusion (CTO). We seek to assess the efficiency of a guide extension catheter-facilitated tip-in technique in comparison to the traditional retrograde approach, which is accomplished by an externalization wire.

Methods

Thirty-three CTO patients successfully revascularized using guide extension catheter-facilitated "tip-in" were included and matched with another 33 patients by J-CTO score and operators, whose CTO was recanalized using an externalized wire. The manipulation time from the first retrograde wire entering the antegrade guide to the first antegrade balloon inflation in the occlusion was calculated.

Results

Compared with the wire-externalization group, the manipulation time in the tip-in group was significantly shortened [389s; interquartile range (IQR), 272-478 vs 706s; IQR, 560-914; p < 0.001]. There was a trend in decreasing total operation time and radiation dose, but it did not reach statistical significance.

Conclusion

Guide extension catheter-facilitated tip-in is an efficient method to achieve the recanalization of CTO in a retrograde way, which would be pivotal when the retrograde microcatheter could not be advanced into the antegrade guide catheter.

Comparison of three fixation methods in paediatric metaphyseal-diaphysis junction fracture of the distal radius: a retrospective study in two centres

Background

The distal radial metaphyseal-diaphysis junction fractures (DRMDJ) have various treatment methods and are easily lead to complications. This study aims to compare the anterograde elastic stable intramedullary nailing (ESIN-A), retrograde K-wire fixation (KW-R), and retrograde precision-shaping elastic intramedullary nailing (ESIN-RPS) for the treatment of pediatric DRMDJ fractures.

Materials and methods

A total of 113 patients with DRMDJ fractures (36 in the ESIN-A group, 52 in the KW-R group, and 25 in the ESIN-RPS group) from two centres were retrospectively analysed. Perioperative operation time, intraoperative bleeding, fluoroscopy times, alignment rate and angulation on radiography were compared among the three groups. Forearm rotation, healing, wrist function, and complications were compared at the last follow-up.

Results

The mean operation times of the three groups were as follows: KW-R (72 ± 13 min) > ESIN-A (65 ± 18 min) > ESIN-RPS (52 ± 11 min), with a significant difference (P < 0.01). The incision length and intraoperative blood loss of ESIN-A (1.8 ± 0.2 cm; 8.3 ± 3.7 ml) were significantly higher than ESIN-RPS (1.4 ± 0.8 cm; 5.5 ± 2.7 ml) (P < 0.05), respectively. The postoperative alignment rate on the anteroposterior (AP) and the lateral plane of ESIN-RPS (93.1 ± 4.4%; 95.01 ± 2.8%) was significantly greater than that of KW-R (82.1 ± 6.8%; 88.5 ± 4.5%) and ESIN-A (79.2 ± 5.2%; 83.2 ± 2.5%) (P < 0.01). The residual angulation of ESIN-RPS (3.3 ± 1.2°; 2.9 ± 0.8°) was significantly greater than that for ESIN-A (5.1 ± 1.7°; 4.9 ± 2.1°) and KW-R (6.6 ± 2.8°; 7.5 ± 1.6°) (P < 0.05). The excellent and good ratio of ESIN-RPS (95.8%) was significantly higher than that of ESIN-A (86.5%) and KW-R (86.1%) according to the Gartland-Werley standard. There was a significant difference in delayed union between the KW-R and ESIN-A (P < 0.05). Additionally, there were two cases of radial nerve injury in the ESIN-A group, one case of tendon rupture in the ESIN-RPS group, and one case of tendon rupture in the KW-R group. The ESIN-RPS group had significantly fewer complications than the KW-R group (P < 0.05). The ESIN-A group also had significantly fewer complications than the KW-R group (P < 0.05).

Conclusion

Compared with ESIN-A and KW-R, ESIN-RPS has the advantages of a shorter operation time, less intraoperative blood loss, less radiation, better alignment, and fewer complications. The ESIN-RPS was suggested as an optimal choice for paediatric DRMDJ fractures.

PCI for Flush Occluded Right Coronary Artery: Challenges and Techniques for Success

A 74-year-old man with prior coronary artery bypass surgery had a failing vein graft to the right coronary artery (RCA). He underwent retrograde chronic total occlusion recanalization of an ostial flush-occluded RCA facilitated by retrograde angioplasty at the aorto-ostial junction after failed retrograde electrocautery. The graft was then sacrificed. (Level of Difficulty: Advanced.).

Single Primary Retrograde Access to Treat Femoro-Popliteal Occlusive Lesions

INTRODUCTION

The retrograde puncture of a distal artery is considered a bailout procedure in case of anterograde approach failure for peripheral artery disease (PAD) treatment. A single primary retrograde access has been suggested as an efficient and safe option. As scant data are available, we present our results using this approach.

MATERIAL AND METHODS

Between August 2019 and October 2022, we performed this technique in selected patients with femoro-popliteal PAD. Chronic total occlusions (CTOs) were selected on the basis of the CTOP classification. An ultrasound-guided retrograde puncture of a tibial artery at the ankle level was performed, followed by the preferential use of 4F materials. Hemostasis of the puncture site was obtained using manual compression. Postoperative duplex scan examination systematically included an evaluation of the punctured artery. Demographics, intraoperative, and follow-up data were collected retrospectively. The results are expressed as means with standard deviations and numbers with percentages when appropriate.

RESULTS

In total, 55 procedures were performed in 46 patients (9 bilateral). Of these, 57% (N=26) were considered at risk for femoral puncture (obesity, history of groin surgery, challenging crossover approach) and 54% (N=25) presented with critical limb-threatening ischemia (CLTI). The TASC-II femoro-popliteal classification was generally B (60%) and also C (33%) or D (7%). Mean lesion length was 105.6±49.4 mm and 65% were CTOs. Most patients were operated in an outpatient setting (N=25; 54%) under potentialized local anesthesia (N=41, 89%). The punctured site was the posterior tibial artery in 73% (N=40). The procedure time was 65.1±25.7 minutes, and the fluoroscopy time was 10.7±8.5 minutes. The technical success rate was 100%. There were no intraoperative complications. All patients could walk the same day. One CLTI patient presented an erysipelas related to the puncture in postoperative period. At 30 days, the primary patency of the treated and the punctured arteries were 98% and 100%, respectively.

CONCLUSION

A single primary retrograde access can be used safely to treat femoro-popliteal PAD. It represents a valuable alternative to the femoral puncture and allows fast ambulation. Prospective and long-term studies on larger populations are necessary to confirm our results.

CLINICAL IMPACT

This study demonstrates that a single primary retrograde access can be used safely without damaging the punctured artery to treat femoro-popliteal lesions, especially in claudicant patients. Chronic total occlusions can be treated successfully using this technique. This approach represents a valuable alternative to the femoral puncture and allows fast ambulation without risk of major bleeding.

Directed stepwise tracing of polysynaptic neuronal circuits with replication-deficient pseudorabies virus

Brain functions are accomplished by polysynaptic circuits formed by neurons wired together through multiple orders of synaptic connections. Polysynaptic connectivity has been difficult to examine due to a lack of methods of continuously tracing the pathways in a controlled manner. Here, we demonstrate directed, stepwise retrograde polysynaptic tracing by inducible reconstitution of replication-deficient trans-neuronal pseudorabies virus (PRVΔIE) in the brain. Furthermore, PRVΔIE replication can be temporally restricted to minimize its neurotoxicity. With this tool, we delineate a wiring diagram between the hippocampus and striatum-two major brain systems for learning, memory, and navigation-that consists of projections from specific hippocampal domains to specific striatal areas via distinct intermediate brain regions. Therefore, this inducible PRVΔIE system provides a tool for dissecting polysynaptic circuits underlying complex brain functions.

Whole-brain neural connectivity to cholinergic neurons in the nucleus basalis of Meynert

The cholinergic neurons in the nucleus basalis of Meynert (NBM) are a key structure in cognition, the dysfunction of which is associated with various neurological disorders, especially dementias. However, the whole-brain neural connectivity to cholinergic neurons in the NBM remains to be further and comprehensively researched. Using virus-based, specific, retrograde, and anterograde tracing, we illustrated the monosynaptic inputs and axon projections of NBM cholinergic neurons in choline acetyltransferase (ChAT)-Cre transgenic mice. Our results showed that NBM cholinergic neurons received mainly inputs from the caudate putamen and the posterior limb of the anterior commissure in the subcortex. Moreover, the majority of cholinergic terminals from the NBM were observed in the cortex mantle, including the motor cortex, sensory cortex, and visual cortex. Interestingly, although NBM cholinergic neurons received input projections from the caudate putamen, interstitial nucleus of the posterior limb of the anterior commissure, and central amygdaloid nucleus, NBM cholinergic neurons sparsely sent axon projection to innervate these areas. Furthermore, primary motor cortex, secondary motor cortex, and primary somatosensory cortex received abundant inputs from the NBM but sent few outputs to the NBM. Taken together, our results reveal the detailed and specific connectivity of cholinergic neurons of the NBM and provide a neuroanatomic foundation for further studies to explore the important physiological functions of NBM cholinergic neurons.

A retrospective review of the rate of septic knee arthritis after retrograde femoral nailing for traumatic femoral fractures at a single academic institution

Background

Retrograde intramedullary nailing of the femur is a popular treatment option for femoral shaft fractures. However, this requires accessing the intramedullary canal through the knee, posing a risk of intra-articular infection. The purpose of this study was to examine the rate of intra-articular infection of the knee after retrograde nailing of femoral shaft fractures.

Methods

All patients who underwent retrograde intramedullary nailing for femoral shaft fractures between June 2004 and December 2017 at a level 1 trauma center were reviewed. Six months of follow-up or documented fracture union was required. Records were reviewed for documentation of septic arthritis of the ipsilateral knee during the follow-up period.

Results

A total of 294 fractures, including 217 closed and 77 open injuries, were included. Eighteen had an associated ipsilateral traumatic arthrotomy; 188 cases had an associated ipsilateral lower extremity fracture. No cases of septic arthritis were identified.

Conclusion

There were no cases of septic arthritis in 294 fractures treated with retrograde intramedullary nailing. Retrograde nailing appears safe for risk of postoperative septic arthritis of the knee even in the face of open fractures and traumatic wounds.

retro-Tango enables versatile retrograde circuit tracing in Drosophila

Transsynaptic tracing methods are crucial tools in studying neural circuits. Although a couple of anterograde tracing methods and a targeted retrograde tool have been developed in Drosophila melanogaster, there is still need for an unbiased, user-friendly, and flexible retrograde tracing system. Here, we describe retro-Tango, a method for transsynaptic, retrograde circuit tracing and manipulation in Drosophila. In this genetically encoded system, a ligand-receptor interaction at the synapse triggers an intracellular signaling cascade that results in reporter gene expression in presynaptic neurons. Importantly, panneuronal expression of the elements of the cascade renders this method versatile, enabling its use not only to test hypotheses but also to generate them. We validate retro-Tango in various circuits and benchmark it by comparing our findings with the electron microscopy reconstruction of the Drosophila hemibrain. Our experiments establish retro-Tango as a key method for circuit tracing in neuroscience research.

Feasibility of pump-controlled retrograde trial off in weaning from veno-arterial ECMO in adults-A single-center case series

BACKGROUND

Various strategies of weaning V-A ECMO have been described. PCRTO is a weaning technique which involves serial decremental pump revolutions until a retrograde flow from the arterial to venous ECMO cannula is achieved. It has been reported as a feasible weaning strategy in the pediatric population, but its application in adults has not been widely reported.

METHODS

This was a case series including all adult patients who underwent PCRTO during weaning from V-A ECMO at a tertiary ECMO center between January 2019 and July 2021. The primary end point was the successful weaning from V-A ECMO support.

RESULTS

A total of 57 runs of PCRTO in 36 patients were analyzed-45 (78.9%) of the trials were concluded successfully. The median retrograde blood flow rate during PCRTO was 0.6 ± 0.2 L/min, and the median duration of each PCRTO was 180 (120-240) min. Of the 35 patients who had at least one session of successful PCRTO, 31 (88.6%) were ultimately weaned from ECMO. There were no major complications from PCRTO including systemic or circuit thrombosis.

CONCLUSIONS

PCRTO is a feasible strategy for assessing readiness for weaning from V-A ECMO with a low risk of adverse events and high rate of predicting eventual successful ECMO decannulation. Further investigation including comparison with alternative weaning strategies in prospective studies is required to confirm the approach.

Experimental Support for the Possibility of Retrograde Genesis of Intraductal Carcinoma of the Prostate

Background. Historically, intraductal carcinoma of the prostate (IDC-P) was postulated to be a retrograde spread of high-grade invasive prostate cancer. There is evidence that IDC-P can primarily originate in the prostatic ducts. The retrograde genesis has never been experimentally or clinically confirmed before. Methods. Biopsy proven intermediate or high-risk prostate cancer was orthotopically grafted in the prostate of severe combined immunodeficiency gamma mice. Cancer growth was monitored by serum PSA levels. The animals were sacrificed and grafted areas were histological examined. Results. Twenty-one of 23 mice survived and demonstrated rising serum PSA. In 10 of 21 animals, human prostate cancer was identified orthotopically. Except for one case where the human biopsy showed a Grade Group 2 prostate cancer and mouse graft was Grade Group 5, other 9 specimens showed comparable grades. One of the specimens demonstrated a cribriform invasive prostate cancer and adjacent IDC-P. Conclusion. These experimental data offer some evidence that invasive prostate cancer can demonstrate a retrograde spread in the prostatic ducts as IDC-P. Its ability to primarily arise in the ducts has been demonstrated in other studies. However, the issue which remains unresolved is in its most common presentation of IDC-P intermixed with high-grade invasive cancer if it is the former or the latter which came first. Possibly resolving this dilemma will shed some light on the existing controversies if IDC-P should or should not be graded when invasive cancer is present.

Indications for retrograde intramedullary screw fixation of the distal fibula: a retrospective cohort series

Introduction

Ankle fractures are a common orthopaedic injury that often require surgical fixation. Because the comorbid population in the United States continues to survive longer, it has become routine to treat comorbid patients with unstable ankle fractures. The literature has identified comorbidities known to increase the risk of ankle fracture complications to include age 55 years or older, body mass index >29.9, polytrauma, open fractures, diabetes mellitus, smoking, peripheral neuropathy, and alcohol use.

Methods

We retrospectively reviewed 37 patients who received retrograde intramedullary screw fixation of the distal fibula, all of whom had preexisting conditions known to increase the rate of postoperative complications.

Results

Thirty-seven patients were included in this study, of whom 36 (97.3%) went on to union. Six of 37 patients (16.2%) had complications although only one (2.7%) was due to inadequate fixation. The average time to weight-bearing as tolerated was 57.2 days (15-115 days). Two patients (5.4%) had symptomatic instrumentation requiring removal after union. Two patients (5.4%) had delayed union of the distal fibula, which responded to the use of a bone stimulator. One patient (2.7%) developed a nonunion which led to chronic subluxation of the ankle joint. One patient (2.7%) had a minor medial ankle wound complication that was treated with oral antibiotics and local wound care.

Conclusions

Retrograde intramedullary screw fixation of the distal fibula is a viable alternative to plate and screw fixation in patients with unstable ankle fractures who have known risk factors for increased complications. However, not all distal fibula fractures are amenable to this fixation method.

Level of Evidence

Level III retrospective cohort study.

[Retrograde Transurethral Contrast-enhanced Ultrasound in the Diagnosis of Bladder Rupture:Report of Two Cases]

Bladder rupture refers to a series of diseases caused by bladder wall laceration and urine flowing into the abdominal cavity.Two cases of bladder rupture diagnosed by retrograde transurethral contrast-enhanced ultrasound were reviewed in this report.We discussed the value of retrograde transurethral contrast-enhanced ultrasound in the diagnosis,classification,and prognosis evaluation of bladder rupture,aiming to provide evidence for clinical diagnosis and treatment.

Retrograde approach for rewiring a jailed side branch during double kissing crush stenting

Double kissing crush (DK crush) is one of the preferred strategies for bifurcation stenting due to the lower risk of target vessel failure but can be difficult to perform. Difficulty in wiring the jailed side branch after stenting the main vessel is not uncommon. The retrograde crossing can provide a solution in selected cases when antegrade rewiring of a jailed side branch fails during DK crush (or other bifurcation stenting techniques).

Distal femur: nail plate combination and the linked construct

Operative fixation of distal femur fractures in patients with osteoporotic bone can be challenging. Treatment with either lateral locking plate or retrograde intramedullary nail alone may not provide adequate fixation to allow for early mobilization. Rather, fixation using the nail plate combination (NPC) to treat distal femur fractures in the elderly may offer improved biomechanical stability to achieve immediate weight-bearing, especially in the setting of complex fracture patterns and osteoporosis. Here, we describe the rationale, step-by-step technique, and outcome following 2 cases: 1 patient treated with a true NPC procedure using retrograde intramedullary nail and standard locking plate, as well as a NPC procedure using a novel locking attaching washer plate.

Neurotensin Release from Dopamine Neurons Drives Long-Term Depression of Substantia Nigra Dopamine Signaling

Midbrain dopamine neurons play central physiological roles in voluntary movement, reward learning, and motivated behavior. Inhibitory signaling at somatodendritic dopamine D2 receptor (D2R) synapses modulates excitability of dopamine neurons. The neuropeptide neurotensin is expressed by many inputs to the midbrain and induces LTD of D2R synaptic currents (LTD_DA); however, the source of neurotensin that is responsible for LTD_DA is not known. Here we show, in brain slices from male and female mice, that LTD_DA is driven by neurotensin released by dopamine neurons themselves. Optogenetic stimulation of dopamine neurons was sufficient to induce LTD_DA in the substantia nigra, but not the VTA, and was dependent on neurotensin receptor signaling, postsynaptic calcium, and vacuolar-type H⁺-ATPase activity in the postsynaptic cell. These findings reveal a novel form of signaling between dopamine neurons involving release of the peptide neurotensin, which may act as a feedforward mechanism to increase dopamine neuron excitability.SIGNIFICANCE STATEMENT Dopamine neurons in the midbrain play a critical role in reward learning and the initiation of movement. Aberrant dopamine neuron function is implicated in a range of diseases and disorders, including Parkinson's disease, schizophrenia, obesity, and substance use disorders. D2 receptor-mediated PSCs are produced by a rare form of dendrodendritic synaptic transmission between dopamine neurons. These D2 receptor-mediated PSCs undergo LTD following application of the neuropeptide neurotensin. Here we show that release of neurotensin by dopamine neurons themselves is sufficient to induce LTD of dopamine transmission in the substantia nigra. Neurotensin signaling therefore mediates a second form of interdopamine neuron communication and may provide a mechanism by which dopamine neurons maintain excitability when nigral dopamine is elevated.

Retrograde Chronic Total Occlusion Percutaneous Coronary Interventions: Predictors of Procedural Success From the ERCTO Registry

OBJECTIVES

The aim of this study was to identify independent predictors of procedural success after retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

BACKGROUND

Retrograde CTO PCI is an established technique, but predictors of success remain poorly understood.

METHODS

A multivariable logistic regression model was used to analyze potentially important demographic, clinical, anatomical, and technical aspects of retrograde CTO PCI cases uploaded to the multicenter European CTO (ERCTO) Club Registry.

RESULTS

In calendar years 2018 and 2019, 2,364 retrograde CTO PCI cases constituted the primary analysis cohort. A primary retrograde strategy was used in 1,953 cases (82.6%), and an initial antegrade approach was converted to retrograde in 411 cases (17.4%). Procedural success was achieved in 1,820 cases (77.0%) and was more likely to occur after a primary retrograde attempt versus conversion from an initial antegrade approach (80.9% vs 58.4%; P < 0.0001). After multivariable analysis, an absence of lesion calcification (OR: 1.86; 95% CI: 1.37-2.51; P < 0.0001), a higher degree of distal vessel opacification (OR: 2.47; 95% CI: 1.72-3.55; P < 0.0001), little or no proximal target vessel tortuosity (OR: 1.84; 95% CI: 1.28-2.64; P = 0.001), Werner collateral connection CC1 (OR: 4.87; 95% CI: 2.90-8.19; P < 0.0001) or CC2 (OR: 5.33; 95% CI: 3.02-9.42; P < 0.0001), and the top tertile of operator volume (>120 cases over 2 years) (OR: 1.88; 95% CI: 1.26-2.79; P = 0.002) were associated with the greatest chance of achieving angiographic success.

CONCLUSIONS

Less calcification with good distal vessel opacification, little or absent proximal vessel tortuosity, and visible collateral connections, along with high-volume operator status, were all independently predictive of angiographically successful retrograde CTO PCI.

Bovine Herpesvirus 1 Invasion of Sensory Neurons by Retrograde Axonal Transport Is Dependent on the pUL37 Region 2 Effector

Following exposure and replication at mucosal surfaces, most alphaherpesviruses invade the peripheral nervous system by retrograde axonal transport and establish lifelong latent infections in the peripheral ganglia. Reactivation of ganglionic infections is followed by anterograde axonal transport of virions back to body surfaces where viral replication results in disease that can range from moderate to severe in presentation. In the case of bovine herpesvirus 1 (BoHV-1), replication in the epithelial mucosa presents as infectious bovine rhinotracheitis (IBR), a respiratory disease of significant economic impact. In this study, we provide a live-cell analysis of BoHV-1 retrograde axonal transport relative to the model alphaherpesvirus pathogen pseudorabies virus (PRV) and demonstrate that this critical neuroinvasive step is conserved between the two viruses. In addition, we report that the BoHV-1 pUL37 tegument protein supports processive retrograde motion in infected axons and invasion of the calf peripheral nervous system. IMPORTANCE A molecular and cellular understanding of the retrograde axonal transport process that underlies the neuroinvasive properties of the alphaherpesviruses is established from studies of herpes simplex virus and pseudorabies virus. The degree to which this phenotype is conserved in other related viruses has largely not been examined. We provide a time-lapse analysis of the retrograde axonal transport kinetics of bovine herpesvirus 1 and demonstrate that mutation of the pUL37 region 2 effector affords a strategy to produce live-attenuated vaccines for enhanced protection of cattle.

Human Papillomavirus L2 Capsid Protein Stabilizes γ-Secretase during Viral Infection

Intracellular trafficking of human papillomavirus (HPV) during virus entry requires γ-secretase, a cellular protease consisting of a complex of four cellular transmembrane (TM) proteins. γ-secretase typically cleaves substrate proteins but it plays a non-canonical role during HPV entry. γ-secretase binds to the HPV minor capsid protein L2 and facilitates its insertion into the endosomal membrane. After insertion, L2 protrudes into the cytoplasm, which allows HPV to bind other cellular factors required for proper virus trafficking into the retrograde transport pathway. Here, we further characterize the interaction between γ-secretase and HPV L2. We show that γ-secretase is required for cytoplasmic protrusion of L2 and that L2 associates strongly with the PS1 catalytic subunit of γ-secretase and stabilizes the γ-secretase complex. Mutational studies revealed that a putative TM domain in HPV16 L2 cannot be replaced by a foreign TM domain, that infectivity of HPV TM mutants is tightly correlated with γ-secretase binding and stabilization, and that the L2 TM domain is required for protrusion of the L2 protein into the cytoplasm. These results provide new insight into the interaction between γ-secretase and L2 and highlight the importance of the native HPV L2 TM domain for proper virus trafficking during entry.

The Long and Winding Road-Vestibular Efferent Anatomy in Mice

The precise functional role of the Efferent Vestibular System (EVS) is still unclear, but the auditory olivocochlear efferent system has served as a reasonable model on the effects of a cholinergic and peptidergic input on inner ear organs. However, it is important to appreciate the similarities and differences in the structure of the two efferent systems, especially within the same animal model. Here, we examine the anatomy of the mouse EVS, from its central origin in the Efferent Vestibular Nucleus (EVN) of the brainstem, to its peripheral terminations in the vestibular organs, and we compare these findings to known mouse olivocochlear anatomy. Using transgenic mouse lines and two different tracing strategies, we examine central and peripheral anatomical patterning, as well as the anatomical pathway of EVS axons as they leave the mouse brainstem. We separately tag the left and right efferent vestibular nuclei (EVN) using Cre-dependent, adeno-associated virus (AAV)-mediated expression of fluorescent reporters to map their central trajectory and their peripheral terminal fields. We couple this with Fluro-Gold retrograde labeling to quantify the proportion of ipsi- and contralaterally projecting cholinergic efferent neurons. As in some other mammals, the mouse EVN comprises one group of neurons located dorsal to the facial genu, close to the vestibular nuclei complex (VNC). There is an average of just 53 EVN neurons with rich dendritic arborizations towards the VNC. The majority of EVN neurons, 55%, project to the contralateral eighth nerve, crossing the midline rostral to the EVN, and 32% project to the ipsilateral eighth nerve. The vestibular organs, therefore, receive bilateral EVN innervation, but without the distinctive zonal innervation patterns suggested in gerbil. Similar to gerbil, however, our data also suggest that individual EVN neurons do not project bilaterally in mice. Taken together, these data provide a detailed map of EVN neurons from the brainstem to the periphery and strong anatomical support for a dominant contralateral efferent innervation in mammals.

Assessment of clinical and radiographic outcomes following retrograde versus antegrade nailing of infraisthmic femoral shaft fractures without the use of intraoperative fluoroscopy in Tanzania

To compare clinical and radiographic outcomes following antegrade versus retrograde intramedullary nailing of infraisthmic femoral shaft fractures.

Design

Secondary analysis of prospective cohort study.

Setting

Tertiary hospital in Tanzania.

Participants

Adult patients with infraisthmic diaphyseal femur fractures.

Intervention

Antegrade or retrograde SIGN intramedullary nail.

Outcomes

Health-related quality of life (HRQOL), radiographic healing, knee range of motion, pain, and alignment (defined as less than or equal to 5 degrees of angular deformity in both coronal and sagittal planes) assessed at 6, 12, 24, and 52 weeks postoperatively.

Results

Of 160 included patients, 141 (88.1%) had 1-year follow-up and were included in analyses: 42 (29.8%) antegrade, 99 (70.2%) retrograde. Antegrade-nailed patients had more loss of coronal alignment (P = .026), but less knee pain at 6 months (P = .017) and increased knee flexion at 6 weeks (P = .021). There were no significant differences in reoperations, HRQOL, hip pain, knee extension, radiographic healing, or sagittal alignment.

Conclusions

Antegrade nailing of infraisthmic femur fractures had higher incidence of alignment loss, but no detectable differences in HRQOL, pain, radiographic healing, or reoperation. Retrograde nailing was associated with increased knee pain and decreased knee range of motion at early time points, but this dissipated by 1 year. To our knowledge, this is the first study to prospectively compare outcomes over 1 year in patients treated with antegrade versus retrograde SIGN intramedullary nailing of infraisthmic femur fractures.Level of Evidence: III.

Immediate retrograde amnesia induced by midazolam: A prospective, non-randomised cohort study

BACKGROUND

Midazolam, a short-acting benzodiazepine, has sedative, anxiolytic, amnestic and anticonvulsant effects. Given its advantages of rapid onset, short duration and low toxicity, midazolam is optimal for any procedural sedation. Midazolam is known to cause anterograde amnesia; however, the possibility of retrograde amnesia has also been raised. This prospective cohort, non-randomised study evaluated the presence and extent of retrograde amnesia induced by midazolam during caesarean delivery.

METHODS

One hundred parturients scheduled for elective caesarean delivery under spinal anaesthesia were enrolled. As soon as giving birth, six picture cards were shown to the patients in 1-min intervals, and then midazolam (0.1 mg/kg) was given or not according to the patients' preference. This overall retrograde recall rate of six cards was the primary outcome of our study, which was asked by a blinded investigator.

RESULTS

The overall retrograde card recall rate was lower in the midazolam group compared with the control group (77.0 ± 13.4 vs. 87.7 ± 3.9%, P < .001), especially at 1 minute before midazolam administration (58% vs. 88%, P < .001). Decreased memory trend was observed as time progressed towards midazolam administration in the midazolam group (P = .035). More patients answered 'yes' to the factitious event in the midazolam group than in the control group (26% vs. 4%, P = .004).

CONCLUSION

Intravenous midazolam could cause a brief-period retrograde amnesia in visual and event memory. Moreover, there were more spurious reports of intraoperative factitious events in the midazolam group, implying that episodic memories were also affected by midazolam.

Immediate retrograde amnesia induced by midazolam: a prospective, nonrandomized cohort study

BACKGROUND

Midazolam, a short-acting benzodiazepine, has sedative, anxiolytic, amnestic, and anticonvulsant effect. Given its advantages of rapid onset, short duration, and low toxicity, midazolam is optimal for any procedural sedation. Midazolam is known to cause anterograde amnesia; however, the possibility of retrograde amnesia has also been raised. This prospective cohort, nonrandomized study evaluated the presence and extent of retrograde amnesia induced by midazolam during cesarean delivery.

METHODS

One-hundred parturients scheduled for elective cesarean delivery under spinal anesthesia were enrolled. As soon as giving birth, 6 picture cards were shown to the patients in one min intervals, and then midazolam (0.1 mg/kg) was given or not according to the patients' preference. This overall retrograde recall rate of six cards was the primary outcome of our study, which was asked by a blinded investigator.

RESULTS

The overall retrograde card recall rate was lower in the midazolam group compared to the control group (77.0 ± 13.4 vs. 87.7 ± 3.9%, p <0.001), especially at one min before midazolam administration (58 vs. 88%, p <0.001). Decreased memory trend was observed as time progressed toward midazolam administration in the midazolam group (p = 0.035). More patients answered 'yes' to the factitious event in the midazolam group than in the control group (26% vs. 4%, p = 0.004).

CONCLUSION

Intravenous midazolam could cause a brief-period retrograde amnesia in visual and event memory. Moreover, there were more spurious reports of intraoperative factitious events in the midazolam group, implying that episodic memories were also affected by midazolam.

Retrograde Revascularization of Tibial Arteries in Patients with Critical Limb Ischemia: Plantar-Arch Versus Transpedal Approach

PURPOSE

To compare retrograde plantar-arch and transpedal-access approach for revascularization of below-the-knee (BTK) arteries in patients with critical limb ischemia (CLI) after a failed antegrade approach.

MATERIALS AND METHODS

Retrospectively we identified 811 patients who underwent BTK revascularization between 1/2014 and 1/2020. In 115/811 patients (14.2%), antegrade revascularization of at least 1 tibial artery had failed. In 67/115 (58.3%), patients retrograde access to the target vessel was achieved via the femoral access and the plantar-arch (PLANTAR-group); and in 48/115 patients (41.7%) retrograde revascularization was performed by an additional retrograde puncture (TRANSPEDAL-group). Comorbidities, presence of calcification at pedal-plantar-loop/transpedal-access-site, and tibial-target-lesion was recorded. Endpoints were technical success (PLANTAR-group: crossing the plantar-arch; TRANSPEDAL-group: intravascular placement of the pedal access sheath), procedural success [residual stenosis <30% after plain old balloon angioplasty (POBA)], and procedural complications limb salvage and survival. Correlations between calcification at access site/tibial-target-lesion and technical/procedural-success were tested.

RESULTS

Technical success was achieved in 50/67 (75%) patients of the PLANTAR-group and in 39/48 (81%) patients of the TRANSPEDAL-group (p=0.1). Procedural success was obtained in 23/67 (34%) patients of the PLANTAR-group and in 25/48 (52%) patients of the TRANSPEDAL-group (p=0.04). In 14/49 (29%) cases with calcification at the pedal-plantar loop, technical success was not achieved (p=0.04), and in 33/44 (75%) patients with calcification at the tibial-target-lesion, procedural success was not attained (PLANTAR-group) (p=0.026). In the TRANSPEDAL-group, correlations between calcification at access site/tibial-target-lesion and technical/procedural-success were not observed (p=0.2/p=0.4). In the PLANTAR-group, minor complications occurred in 13/67 (19%) and in the TRANSPEDAL-group in 4/48 patients (8%) (p=0.08). Limb salvage at 12 (18) months was 90% (82%) (PLANTAR-group; 95%CI 15.771-18.061) and 84% (76%) (TRANSPEDAL-group; 95%CI 14.475-17.823) (Log-rank p=0.46). Survival at 12 (18) months was 94% (86%) (PLANTAR-group; 95%CI 16.642-18.337) and 85% (77%) (TRANSPEDAL; 95%CI 14.296-17.621) (Log-rank p=0.098).

CONCLUSION

Procedural success was significantly higher using the transpedal-access approach. Calcifications at pedal-plantar loop and target-lesion significantly influenced technical/procedural failure using the plantar-arch approach. No significant difference between both retrograde techniques in terms of feasibility, safety, and limb salvage/survival was found.

Femoral versus axillary cannulation in acute type A aortic dissections: A meta-analysis

OBJECTIVE

There has been a growing interest in antegrade cannulation techniques in type A aortic dissection surgery. Axillary cannulation has previously been reported to provide better outcomes in terms of short-term mortality and neurological event. Consensus regarding the best cannulation strategy still remains controversial.

METHOD

The MEDLINE and EMBASE databases were conducted up until October 3, 2020. Data regarding mortality, stroke, reoperation for bleeding and length of hospital stay, wound infection and cardiopulmonary bypass time were extracted and submitted to a meta-analysis using random-effects modelling and the I² -test for heterogeneity. Fourteen retrospective observational studies were included, enrolling a total of 2621 patients.

RESULTS

There were a total of 2621 patients (1327 axillary cannulation and 874 femoral cannulation). Axillary cannulation was associated with reduced short term mortality (pooled odds ratio [OR] = +0.42, 95% confidence interval [CI] = +0.25 to +0.70; p = .0009) compared to femoral cannulation. Axillary cannulation was also associated with a lower incidence of neurological events (pooled OR = +0.63, 95% CI = +0.42 to +0.94; p = .02).

CONCLUSION

Our meta-analyses suggests that axillary cannulation has superior outcomes in terms of mortality and stroke following emergency surgery for type A aortic dissection. However, the lack of high quality randomized controlled trials does not make this recommendation generalisable to all units.

A new combined antegrade and retrograde approach for chronic total occlusion recanalization: Facilitated antegrade fenestration and re-entry

While antegrade techniques remain the cornerstone of chronic total occlusion (CTO) percutaneous coronary intervention (PCI), operators have often to resort to the retrograde approach in complex occlusions. In particular, lesions with proximal cap ambiguity, unclear vessel course and/or poor distal landing zone are difficult to tackle with either antegrade wiring or antegrade dissection and re-entry (ADR), and often require the retrograde approach. After collateral channel crossing, the retrograde approach usually culminates with either reverse controlled antegrade and retrograde subintimal tracking (CART) or retrograde true lumen crossing. Both techniques usually involve the use of an externalization wire, which requires keeping a higher activate clotting time to prevent thrombosis of the retrograde channel and is potentially associated with risk for donor vessel injury. In 2018, we described antegrade fenestration and re-entry (AFR), a targeted ADR technique in which fenestrations between the false and true lumen are created by antegrade balloon dilatation in the extraplaque space at the level of the distal cap, which are subsequently engaged by a polymer-jacketed wire to achieve re-entry. We hypothesized that AFR can also expedite antegrade crossing of the CTO after a wire has reached the distal vessel in a retrograde fashion. In this report, we present two cases in which we successfully achieved antegrade CTO crossing with AFR following retrograde advancement of a guidewire to the distal cap, in new variant of the technique, which we called "facilitated AFR".

Dendritic Localization and Exocytosis of NAAG in the Rat Hippocampus

While a lot is known about classical, anterograde neurotransmission, less is known about the mechanisms and molecules involved in retrograde neurotransmission. Our hypothesis is that N-acetylaspartylglutamate (NAAG), the most abundant dipeptide in the brain, may act as a retrograde transmitter in the brain. NAAG was predominantly localized in dendritic compartments of glutamatergic synapses in the intact hippocampus, where it was present in close proximity to synaptic-like vesicles. In acute hippocampal slices, NAAG was depleted from postsynaptic dendritic elements during neuronal stimulation induced by depolarizing concentrations of potassium or by exposure to glutamate receptor (GluR) agonists. The depletion was completely blocked by botulinum toxin B and strictly dependent on extracellular calcium, indicating exocytotic release. In contrast, there were low levels of NAAG and no effect by depolarization or GluR agonists in presynaptic glutamatergic terminals or GABAergic pre- and postsynaptic elements. Together these data suggest a possible role for NAAG as a retrograde signaling molecule at glutamatergic synapses via exocytotic release.

Trans-synaptic degeneration in the visual pathway: Neural connectivity, pathophysiology, and clinical implications in neurodegenerative disorders

There is a strong interrelationship between eye and brain diseases. It has been shown that neurodegenerative changes can spread bidirectionally in the visual pathway along neuronal projections. For example, damage to retinal ganglion cells in the retina leads to degeneration of the visual cortex (anterograde degeneration) and vice versa (retrograde degeneration). The underlying mechanisms of this process, known as trans-synaptic degeneration (TSD), are unknown, but TSD contributes to the progression of numerous neurodegenerative disorders, leading to clinical and functional deterioration. The hierarchical structure of the visual system comprises of a strong topographic connectivity between the retina and the visual cortex and therefore serves as an ideal model to study the cellular effect, clinical manifestations, and deterioration extent of TSD. With this review we provide comprehensive information about the neural connectivity, synapse function, molecular changes, and pathophysiology of TSD in visual pathways. We then discuss its bidirectional nature and clinical implications in neurodegenerative diseases. A thorough understanding of TSD in the visual pathway can provide insights into progression of neurodegenerative disorders and its potential as a therapeutic target.

Distinct Populations of Amygdala Somatostatin-Expressing Neurons Project to the Nucleus of the Solitary Tract and Parabrachial Nucleus

Rostral forebrain structures, such as the central nucleus of the amygdala (CeA), send projections to the nucleus of the solitary tract (NST) and the parabrachial nucleus (PBN) that modulate taste-elicited responses. However, the proportion of forebrain-induced excitatory and inhibitory effects often differs when taste cell recording changes from the NST to the PBN. The present study investigated whether this descending influence might originate from a shared or distinct population of neurons marked by expression of somatostatin (Sst). In Sst-reporter mice, the retrograde tracers' cholera toxin subunit B AlexaFluor-488 and -647 conjugates were injected into the taste-responsive regions of the NST and the ipsilateral PBN. In Sst-cre mice, the cre-dependent retrograde tracers' enhanced yellow fluorescent protein Herpes Simplex Virus (HSV) and mCherry fluorescent protein HSV were injected into the NST and the ipsilateral PBN. The results showed that ~40% of CeA-to-PBN neurons expressed Sst compared with ~ 23% of CeA-to-NST neurons. For both the CeA Sst-positive and -negative populations, the vast majority projected to the NST or PBN but not both nuclei. Thus, a subset of CeA-to-NST and CeA-to-PBN neurons are marked by Sst expression and are largely distinct from one another. Separate populations of CeA/Sst neurons projecting to the NST and PBN suggest that differential modulation of taste processing might, in part, rely on differences in local brainstem/forebrain synaptic connections.

Outcomes of retrograde chronic total occlusion percutaneous coronary intervention: A report from the OPEN-CTO registry

OBJECTIVES

We sought to assess in-hospital and long-term outcomes of retrograde compared with antegrade-only percutaneous coronary intervention for chronic total occlusion (CTO PCI).

BACKGROUND

Procedural and clinical outcomes following retrograde compared with antegrade-only CTO PCI remain unknown.

METHODS

Using the core-lab adjudicated OPEN-CTO registry, we compared the outcomes of retrograde to antegrade-only CTO PCI. Primary endpoints included were in-hospital major adverse cardiac and cerebrovascular events (MACCE) (all-cause death, stroke, myocardial infarction [MI], emergency cardiac surgery, or clinically significant perforation) and MACCE at 1-year (all-cause death, MI, stroke, target lesion revascularization, or target vessel reocclusion).

RESULTS

Among 885 single CTO procedures from the OPEN-CTO registry, 454 were retrograde and 431 were antegrade-only. Lesion complexity was higher (J-CTO score: 2.7 vs. 1.9; p < .001) and technical success lower (82.4 vs. 94.2%; p < .001) in retrograde compared with antegrade-only procedures. All-cause death was higher in the retrograde group in-hospital (2 vs. 0%; p = .003), but not at 1-year (4.9 vs. 3.3%; p = .29). Compared with antegrade-only procedures, in-hospital MACCE rates (composite of all-cause death, stroke, MI, emergency cardiac surgery, and clinically significant perforation) were higher in the retrograde group (10.8 vs. 3.3%; p < .001) and at 1-year (19.5 vs. 13.9%; p = .03). In sensitivity analyses landmarked at discharge, there was no difference in MACCE rates at 1 year following retrograde versus antegrade-only CTO PCI. Improvements in Seattle Angina Questionnaire Quality of Life scores at 1-year were similar between the retrograde and antegrade-only groups (29.9 vs 30.4; p = .58).

CONCLUSIONS

In the OPEN-CTO registry, retrograde CTO procedures were associated with higher rates of in-hospital MACCE compared with antegrade-only; however, post-discharge outcomes, including quality of life improvements, were similar between technical modalities.

Retrograde Axonal Transport Property of Adeno-Associated Virus and Its Possible Application in Future

Gene therapy has become a treatment method for many diseases. Adeno-associated virus (AAV) is one of the most common virus vectors, is also widely used in the gene therapy field. During the past 2 decades, the retrograde axonal transportability of AAV has been discovered and utilized. Many studies have worked on the retrograde axonal transportability of AAV, and more and more people are interested in this field. This review described the current application, influence factors, and mechanism of retrograde axonal transportability of AAV and predicted its potential use in disease treatment in near future.

Intra-articular Fracture Pattern in Intercondylar Distal Femur Fractures: An Analysis of Frequency and Major Fracture Fragments

INTRODUCTION

The treatment of intercondylar distal femur fractures requires anatomic reduction of intra-articular fragments and absolute fixation. Preoperative planning is necessary to understand fracture morphology. All fracture lines need to be recognized as the primary implant may not capture all articular fragments, mainly when coronal plane fractures are present. Oftentimes, independent interfragmentary compression screws are necessary. No recent studies have visually mapped out the distal femur articular fracture fragments necessary for absolute fixation. The objectives of this study are to determine the frequency of coronal plane fractures in intercondylar distal femur fractures and describe the pattern of intra-articular fracture fragments.

MATERIALS AND METHODS

The hospital's trauma registry was queried for distal femur ORIF CPT codes logged in the past four years. A retrospective chart review was performed using the EMR and CT scans. Demographics and mechanisms of injury were analyzed. Fracture fragments were surveyed and drawn out by hand on a template for easy organization. Patients' fractures were categorized into the following groups: fractures with no intra-articular coronal plane fractures, those with medial coronal fractures, those with lateral coronal fractures, or those with both medial and lateral coronal fractures. Major fracture fragments were identified.

RESULTS

A total of 55 patients were included. 26 patients (47%) were found to have no intra-articular coronal plane fractures; 6 patients (11%) were found to have medial coronal plane fractures; 15 patients (27%) were found to have lateral coronal plane fractures, and 8 patients (15%) had medial and lateral coronal plane fractures. Collectively, intra-articular coronal plane fractures were identified in 29 patients (53%) with intercondylar distal femur fractures. Four major fracture fragments along with intercondylar and condylar comminution sites were identified.

DISCUSSION

Distal femur intra-articular coronal plane fractures can yield large anterior and posterior condylar fracture fragments of either the medial condyle, lateral condyle, or both condyles. Coronal plane fracture fragments must be identified to obtain absolute fixation. Our study found a higher coronal plane fracture line frequency (52.7%) than prior commonly cited studies. Surgeons must be on the lookout for anterior fracture fragments, posterior fracture fragments, and articular comminution when treating intercondylar femur fractures.

The FTLD Risk Factor TMEM106B Regulates the Transport of Lysosomes at the Axon Initial Segment of Motoneurons

Genetic variations in TMEM106B, coding for a lysosomal membrane protein, affect frontotemporal lobar degeneration (FTLD) in GRN- (coding for progranulin) and C9orf72-expansion carriers and might play a role in aging. To determine the physiological function of TMEM106B, we generated TMEM106B-deficient mice. These mice develop proximal axonal swellings caused by drastically enlarged LAMP1-positive vacuoles, increased retrograde axonal transport of lysosomes, and accumulation of lipofuscin and autophagosomes. Giant vacuoles specifically accumulate at the distal end and within the axon initial segment, but not in peripheral nerves or at axon terminals, resulting in an impaired facial-nerve-dependent motor performance. These data implicate TMEM106B in mediating the axonal transport of LAMP1-positive organelles in motoneurons and axonal sorting at the initial segment. Our data provide mechanistic insight into how TMEM106B affects lysosomal proteolysis and degradative capacity in neurons.

Hsc70 Facilitates Mannose-6-Phosphate Receptor-Mediated Intracellular Trafficking and Enhances Endosomal Release of Phosphorothioate-Modified Antisense Oligonucleotides

Phosphorothioate-modified antisense oligonucleotide (PS-ASO) drugs are commonly used to modulate gene expression through RNase H1-mediated cleavage of target RNAs. Upon internalization through endocytic pathways into cells, PS-ASOs must be released from membraned endosomal organelles to act on target RNAs, a limiting step of PS-ASO activity. Here we report that Hsc70 protein mediates productive release of PS-ASOs from endosomes. Hsc70 protein was enriched in endosome fractions shortly after PS-ASO incubation with cells. Reduction of Hsc70 significantly decreased the activities of PS-ASOs in reducing target RNAs. PS-ASO uptake and transport from early endosomes to late endosomes (LEs) were not affected upon Hsc70 reduction; however, endosomal release of PS-ASOs was impaired. Reduction of Hsc70 led to more scattered mannose-6-phosphate receptor (M6PR) localization at LEs in the cytoplasm, in contrast to the perinuclear localization at trans-Golgi network (TGN) in control cells, suggesting that retrograde transport of M6PR from LEs to TGN was affected. Consistently, reduction of Hsc70 increased colocalization of M6PR and PS-ASOs at LEs, and also delayed M6PR antibody transport from LE to TGN. Together, these results suggest that Hsc70 protein is involved in M6PR vesicle escape from LEs and may thus enhance PS-ASO release from LEs.

Retrograde Intussusception of Distal Limb of Loop Ileostomy: A Rare Case Report and Review of Literature

Stoma related complications affect the quality of life and may require another intervention for correction. Intussusception of either limb through a stoma is a rare complication which can be easily missed. Delay in presentation and diagnosis complicates the matter, necessitates laparotomy and resection of more bowel, ultimately increases the morbidity of the patient. Distal limb usually is empty and collapsed because of minimal function. Distal limb complications are rare. We report a case of intussusception of distal limb through loop ileostomy, which was diagnosed early and managed through local exploration.

The Efficacy and Medium to Long-Term Follow-Up of Transcatheter Retrograde Closure of Perimembranous Ventricular Septal Defects via the Femoral Artery With Amplatzer Duct Occluder II in Children

Objective: The aim of this study was to assess the efficacy and safety of transcatheter retrograde closure of perimembranous ventricular septal defect (pmVSD) via the femoral artery with an Amplatzer Duct Occluder II (ADO II) in children. Methods: The clinical and follow-up data of 102 children who had successfully undergone transcatheter retrograde closure of pmVSD via the femoral artery with Amplatzer Duct Occluder II (ADO II) from February 2012 to June 2019 in our center were retrospectively reviewed. Results: In 102 of 103 patients, the defects were successfully closed (99.0%). The average age was 4.03 ± 1.84 years and the mean weight was 17.50 ± 5.58 kg. The mean diameter of the defects was 2.58 ± 0.63 mm. Hundred of the occluders had a waist length of 4 mm. The complete closure rate was 89.2% 24 h after the procedure and 98% at the last follow-up. The follow-up period ranged from 6 to 92 months, with a median of 36 months. One child developed new mild aortic regurgitation (AR), and 9 patients developed new mild tricuspid regurgitation (TR). During follow-up, TR disappeared in 5 patients and decreased in 4 patients, and AR relieved in one patient. One patient developed intermittent complete left bundle branch block 4 days after the procedure and recovered sinus rhythm 2 days later. No serious complications occurred. Conclusion: Transcatheter retrograde closure of pmVSD via the femoral artery with ADO II in children is safe, feasible, and effective in selected patients.