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Neural Regeneration Research Dec 2023The peripheral nervous system has an extensive branching organization, and peripheral nerve injuries that ablate branch points present a complex challenge for clinical... (Review)
Review
The peripheral nervous system has an extensive branching organization, and peripheral nerve injuries that ablate branch points present a complex challenge for clinical repair. Ablations of linear segments of the PNS have been extensively studied and routinely treated with autografts, acellular nerve allografts, conduits, wraps, and nerve transfers. In contrast, segmental-loss peripheral nerve injuries, in which one or more branch points are ablated so that there are three or more nerve endings, present additional complications that have not been rigorously studied or documented. This review discusses: (1) the branched anatomy of the peripheral nervous system, (2) case reports describing how peripheral nerve injuries with branched ablations have been surgically managed, (3) factors known to influence regeneration through branched nerve structures, (4) techniques and models of branched peripheral nerve injuries in animal models, and (5) conclusions regarding outcome measures and studies needed to improve understanding of regeneration through ablated branched structures of the peripheral nervous system.
PubMed: 37449590
DOI: 10.4103/1673-5374.373679 -
Frontiers in Cellular Neuroscience 2022Segmental peripheral nerve injuries (PNI) are the most common cause of enduring nervous system dysfunction. The peripheral nervous system (PNS) has an extensive and...
Segmental peripheral nerve injuries (PNI) are the most common cause of enduring nervous system dysfunction. The peripheral nervous system (PNS) has an extensive and highly branching organization. While much is known about the factors that affect regeneration through sharp bisections and linear ablations of peripheral nerves, very little has been investigated or documented about PNIs that ablate branch points. Such injuries present additional complexity compared to linear segmental defects. This study compared outcomes following ablation of a branch point with branched grafts, specifically examining how graft source and orientation of the branched graft contributed to regeneration. The model system was Lewis rats that underwent a 2.5 cm ablation that started in the sciatic nerve trunk and included the peroneal/tibial branch point. Rats received grafts that were rat sciatic autograft, inbred sciatic allograft, and inbred femoral allograft, each of which was a branched graft of 2.5 cm. Allografts were obtained from Lewis rats, which is an inbred strain. Both branches of the sciatic grafts were mixed motor and sensory while the femoral grafts were smaller in diameter than sciatic grafts and one branch of the femoral graft is sensory and the other motor. All branched grafts were sutured into the defect in two orientations dictated by which branch in the graft was sutured to the tibial vs peroneal stumps in recipients. Outcome measures include compound muscle action potentials (CMAPs) and CatWalk gait analysis throughout the recovery period, with toluidine blue for intrinsic nerve morphometry and retrograde labeling conducted at the 36-week experimental end point. Results indicate that graft source and orientation does play a significant role earlier in the regenerative process but by 36 weeks all groups showed very similar indications of regeneration across multiple outcomes.
PubMed: 36451654
DOI: 10.3389/fncel.2022.1055490 -
Anatomical Record (Hoboken, N.J. : 2007) Apr 2019The hypoglossal or twelfth cranial nerve is the motor nerve to the extrinsic and intrinsic muscles of the tongue, and the superior root of the ansa cervicalis and the...
The hypoglossal or twelfth cranial nerve is the motor nerve to the extrinsic and intrinsic muscles of the tongue, and the superior root of the ansa cervicalis and the thyrohyoid and geniohyoid branches are delivered through the nerve. This study investigated the muscular branches of the hypoglossal nerve to clarify their spatial relationships with the muscles of the tongue and the neighboring structures. The muscles and the nerve were gross anatomically examined in 42 cadavers. The superior root and the thyrohyoid branch left the nerve near the occipital and lingual arteries, respectively. The extrinsic muscles consisted of some components, and the geniohyoid branch and the lingual branches arose on the hyoglossus. The ascending lingual branches formed a plexus on the anterior part of the hyoglossus and were divided into the proximal and distal groups. They supplied the two parts of the hyoglossus, the three bundles of the styloglossus and the superior and inferior longitudinal muscles and communicated with the lingual nerve. The descending lingual branches supplied the inferior part of the genioglossus, and the terminal branches gave intramuscular twigs to its main part and the transverse and vertical muscles. The findings indicated that the branching pattern of the hypoglossal nerve is characterized by the positional relationships to the components of the extrinsic muscles. The hyoid bone can be an effective marker to identify the branches and affected position if it was used in combination with the morphology of the extrinsic muscles, and the knowledge of their variations is also beneficial. Anat Rec, 302:558-567, 2019. © 2018 Wiley Periodicals, Inc.
Topics: Aged; Female; Humans; Hypoglossal Nerve; Lingual Nerve; Male; Muscles; Tongue
PubMed: 29659197
DOI: 10.1002/ar.23819 -
Folia Morphologica 2021The current study aims to determine the prevalence of variations of the aortic arch using computed tomography angiography (CTA), as well as morphometries and gender... (Observational Study)
Observational Study
BACKGROUND
The current study aims to determine the prevalence of variations of the aortic arch using computed tomography angiography (CTA), as well as morphometries and gender correlations.
MATERIALS AND METHODS
A retrospective, transverse, observational and descriptive study of 220 CTA was performed. The branching pattern, most cranial vertebral level of the aortic arch, area of the proximal, middle and distal segments of the arch, area of each branch, and the path of atypical arteries were recorded. Results were analysed and stratified by gender.
RESULTS
The typical aortic arch branching pattern was present in 77.7% without statistical significance between genders. The most common variant was a two-branch pattern with a common trunk and a left subclavian (13.6%), followed by a typical branching pattern with an added left vertebral artery (7.3%). T3 was the most frequent cranial level (32.3%), followed by T2-T3 (26.8%), and T3-T4 (23.2%). The mean areas of the aortic arch were 685.5 ± 183.9, 476.1 ± 124.1, and 445.0 ± 145.1 mm2 for the proximal, middle and distal segments, with statistical difference between men and women in the middle and distal segments. Three paths of atypical arteries were identified: bifurcated vertebral artery (0.5%), aberrant right subclavian artery (0.5%), and left subclavian ostium obstruction (0.5%).
CONCLUSIONS
Mexican population has one of the highest prevalence of variations in the aortic arch branching pattern. The high probability of finding these should be taken into consideration when assessing patients. A standardised classification method would contemplate future un-reported findings, without causing confusion by the different numbers assigned by each author.
Topics: Aorta, Thoracic; Cardiovascular Abnormalities; Computed Tomography Angiography; Female; Humans; Male; Retrospective Studies; Subclavian Artery
PubMed: 32844389
DOI: 10.5603/FM.a2020.0098 -
Skeletal Muscle Aug 2023The occurrence of hyperplasia, through myofibre splitting, remains a widely debated phenomenon. Structural alterations and fibre typing of skeletal muscle fibres, as...
BACKGROUND
The occurrence of hyperplasia, through myofibre splitting, remains a widely debated phenomenon. Structural alterations and fibre typing of skeletal muscle fibres, as seen during regeneration and in certain muscle diseases, can be challenging to interpret. Neuromuscular electrical stimulation can induce myofibre necrosis followed by changes in spatial and temporal cellular processes. Thirty days following electrical stimulation, remnants of regeneration can be seen in the myofibre and its basement membrane as the presence of small myofibres and encroachment of sarcolemma and basement membrane (suggestive of myofibre branching/splitting). The purpose of this study was to investigate myofibre branching and fibre type in a systematic manner in human skeletal muscle undergoing adult regenerative myogenesis.
METHODS
Electrical stimulation was used to induce myofibre necrosis to the vastus lateralis muscle of one leg in 5 young healthy males. Muscle tissue samples were collected from the stimulated leg 30 days later and from the control leg for comparison. Biopsies were sectioned and stained for dystrophin and laminin to label the sarcolemma and basement membrane, respectively, as well as ATPase, and antibodies against types I and II myosin, and embryonic and neonatal myosin. Myofibre branches were followed through 22 serial Sects. (264 μm). Single fibres and tissue blocks were examined by confocal and electron microscopy, respectively.
RESULTS
Regular branching of small myofibre segments was observed (median length 144 μm), most of which were observed to fuse further along the parent fibre. Central nuclei were frequently observed at the point of branching/fusion. The branch commonly presented with a more immature profile (nestin + , neonatal myosin + , disorganised myofilaments) than the parent myofibre, together suggesting fusion of the branch, rather than splitting. Of the 210 regenerating muscle fibres evaluated, 99.5% were type II fibres, indicating preferential damage to type II fibres with our protocol. Furthermore, these fibres demonstrated 7 different stages of "fibre-type" profiles.
CONCLUSIONS
By studying the regenerating tissue 30 days later with a range of microscopy techniques, we find that so-called myofibre branching or splitting is more likely to be fusion of myotubes and is therefore explained by incomplete regeneration after a necrosis-inducing event.
Topics: Male; Adult; Infant, Newborn; Humans; Muscle Fibers, Skeletal; Muscle, Skeletal; Regeneration; Myosins; Necrosis
PubMed: 37573332
DOI: 10.1186/s13395-023-00322-2 -
Journal of Vascular Surgery Aug 2021We investigated the effect of the length and tortuosity of directional branches on the mid-term outcomes of branched endovascular aneurysm repair (BEVAR) for...
OBJECTIVE
We investigated the effect of the length and tortuosity of directional branches on the mid-term outcomes of branched endovascular aneurysm repair (BEVAR) for thoracoabdominal aortic aneurysms (TAAA).
METHODS
We retrospectively reviewed single-center data of consecutive patients who had undergone BEVAR for TAAA from 2015 to 2019. Three-dimensional computed tomography angiogram reconstructions (Aquarius iNtuition software; TeraRecon, Durham, NC) of the first postoperative imaging studies were used to measure the branch total length (TL), branch vertical length (VL), and branch tortuosity index (TI). The branch TL was measured as the centerline distance between the branch proximal radiopaque marker and the distal edge of the bridging stent. The VL was measured as the centerline distance between the branch distal radiopaque marker and the origin of the target artery. The TI was measured in accordance with the Society for Vascular Surgery reporting standard. The primary end point was freedom from branch instability, defined as any branch-related death, occlusion, or rupture and any reintervention for stenosis, endoleak, or disconnection. Cox proportional hazards were used to identify predictors of branch instability. A penalized spline function was used to identify the relationship between branch instability and the branch TL and VL.
RESULTS
Postimplantation analysis was conducted on 32 TAAAs (extent I-III, n = 18 [56%]; extent IV, n = 14 [44%]), with 123 arteries included through a directional branch. A covered self-expanding bridging stent was used in all cases. Intraoperative reinforcement with an additional bare metal stent was performed in 85 cases (69%). The overall freedom from branch instability at 3 years was 88% (95% confidence interval [CI], 81%-94%). Five cases of occlusion and eight cases of branch-related endoleak occurred. A concomitant endoleak and severe stenosis requiring intervention developed in three cases. The Cox model with splines showed that the minimal risk of branch instability was achieved with a branch TL of 60 to 100 mm (P = .002) and a branch VL of 25 to 50 mm (P = .038). A TI of >1.15 was a predictor of branch complications (hazard ratio [HR], 8.6; 95% CI, 2.4-31.4; P < .001). After multivariate analysis, aneurysm diameter (HR, 1.08; 95% CI, 0.03-1.15; P = .003), TI >1.15 (HR, 6.81; 95% CI, 2.17-27.33; P < .001), and TL <60 or >100 mm (P = .002) were significantly associated with branch instability.
CONCLUSIONS
The branch length and TI seemed to play an important role in BEVAR outcomes. The lowest branch instability rates were obtained with a branch TL of 60 to 100 mm, and this should be considered during planning and implantation. A branch TI >1.15 might require a more strict monitoring to prevent mid- and long-term complications.
Topics: Aged; Aortic Aneurysm, Thoracic; Aortography; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Computed Tomography Angiography; Endovascular Procedures; Female; Humans; Male; Middle Aged; Postoperative Complications; Prosthesis Design; Retreatment; Retrospective Studies; Risk Assessment; Risk Factors; Stents; Time Factors; Treatment Outcome
PubMed: 33383109
DOI: 10.1016/j.jvs.2020.12.078 -
The Journal of Thoracic and... Jul 2021The preliminary clinical outcomes of a novel branch stent-grafting for endovascular repair of chronic aortic arch dissection proved its safety and effectiveness.
BACKGROUND
The preliminary clinical outcomes of a novel branch stent-grafting for endovascular repair of chronic aortic arch dissection proved its safety and effectiveness.
OBJECTIVE
The purpose of this study is to present the long-term outcomes and evaluate the durability of this novel endovascular therapy.
METHODS
Between August 2009 and January 2014, 51 patients with aortic dissections involving arch branches were treated by the endovascular stent-grafting. There were 7 Stanford type A aortic dissections, 22 retrograde type A aortic dissections, and 22 Stanford type B aortic dissections. The supra-arch branch arteries were reconstructed by individualized strategies.
RESULTS
All the proximal entry tears in arch were successfully excluded, and no type I/III endoleaks occurred. The median follow-up period was 92 months (range, 62-114 months). A total of 7 complications, 4 deaths, and 3 reinterventions occurred. There were 2 deaths from retrograde type A aortic dissections, 1 death from cerebral infarction, and 1 death from malignant tumor. The incidence of complications, reintervention, all-cause mortality, and aorta-related mortality was 0.035%/patient-year, 0.015%/patient-year, 0.020%/patient-year, and 0.010%/patient-year, respectively. The patency rate of cervical bypass was 90.1%. The significant true lumen recovery and false lumen shrinkage were observed at the 4 designated levels of the thoracic aorta according to computed tomography angiography images.
CONCLUSIONS
Based on preoperatively adequate planning and accurate measurement, endovascular repair of chronic aortic arch dissection using this branched stent-graft showed a low and an acceptable incidence of complications and mortality with positive aortic remodeling, which provided a satisfactory and promising alternative treatment option.
Topics: Aged; Aortic Dissection; Aortic Aneurysm, Thoracic; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Chronic Disease; Databases, Factual; Endovascular Procedures; Female; Follow-Up Studies; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Postoperative Complications; Reoperation; Stents; Treatment Outcome
PubMed: 31926697
DOI: 10.1016/j.jtcvs.2019.10.184 -
Journal of Vascular Surgery Apr 2020The aim of this study was to investigate the incidence and impact of acute and chronic kidney dysfunction after branched endovascular aortic aneurysm repair (BEVAR)...
OBJECTIVE
The aim of this study was to investigate the incidence and impact of acute and chronic kidney dysfunction after branched endovascular aortic aneurysm repair (BEVAR) perioperatively and during follow-up.
METHODS
Patients with a thoracoabdominal aortic aneurysm were treated with BEVAR. Serum creatinine; estimated glomerular filtration rate at baseline, after 48 hours, at discharge, and after 1 and two years; perioperative results; and outcome during follow-up were evaluated.
RESULTS
Treatment of thoracoabdominal aortic aneurysm using BEVAR was performed in 113 patients (mean age, 71 years; 79 male) with 434 side branches and two additional fenestrations (0.46%) for renovisceral perfusion. Sixty patients (53%) underwent staged procedures with temporary aneurysm sac perfusion and secondary side branch completion. Perioperative mortality was 9 of 113 (8%). Postoperative acute kidney injury (AKI) was observed in 41 of 113 patients (36%) with recovery of renal function after 2 years in most patients. However, chronic kidney disease (CKD) stage progression after 1 and 2 years was observed in 25 of 104 patients (24%) and 17 of 52 patients (32.7%), respectively. Seven patients (6.7%) required permanent dialysis during 2 years of follow-up. Risk factors for AKI were nonstaged procedures (P = .02) and multiorgan failure (P = .01). CKD progression was related to renal branch reinterventions (P = .047), all branch reinterventions (P = .03), and postoperative AKI (P = .001). During follow-up, survival was decreased in patients with AKI, especially in those with nonmalignant diseases (P = .01).
CONCLUSIONS
Postoperative AKI after BEVAR was observed in about one-third of patients associated with increased CKD stages after 2 years. Preoperative CKD was not a risk factor for postoperative AKI or perioperative outcome. The prevention of AKI by staged procedures, early interventions for renal side branch complications, and regular surveillance is recommended to improve outcomes.
Topics: Aged; Aortic Aneurysm, Thoracic; Disease Progression; Endovascular Procedures; Female; Humans; Kidney Function Tests; Male; Postoperative Complications; Renal Insufficiency; Risk Factors
PubMed: 31791742
DOI: 10.1016/j.jvs.2019.06.200