Distal Stump Research Articles

Utilization of the Rat Tibial Nerve Transection Model to Evaluate Cellular and Molecular Mechanisms Underpinning Denervation-Mediated Muscle Injury.

Peripheral nerve injury denervates muscle, resulting in muscle paralysis and atrophy. This is reversible if timely muscle reinnervation occurs. With delayed reinnervation, the muscle's reparative ability declines, and muscle-resident fibro-adipogenic progenitor cells (FAPs) proliferate and differentiate, inducing fibro-fatty muscle degradation and thereby physical disability. The mechanisms by which the peripheral nerve regulates FAPs expansion and differentiation are incompletely understood. Using the rat tibial neve transection model, we demonstrated an increased FAPs content and a changing FAPs phenotype, with an increased capacity for adipocyte and fibroblast differentiation, in gastrocnemius muscle post-denervation. The FAPs response was inhibited by immediate tibial nerve repair with muscle reinnervation via neuromuscular junctions (NMJs) and sensory organs (e.g., muscle spindles) or the sensory protection of muscle (where a pure sensory nerve is sutured to the distal tibial nerve stump) with reinnervation by muscle spindles alone. We found that both procedures reduced denervation-mediated increases in glial-cell-line-derived neurotrophic factor (GDNF) in muscle and that GDNF promoted FAPs adipogenic and fibrogenic differentiation in vitro. These results suggest that the peripheral nerve controls FAPs recruitment and differentiation via the modulation of muscle GDNF expression through NMJs and muscle spindles. GDNF can serve as a therapeutic target in the management of denervation-induced muscle injury.

Brief Electrical Stimulation Promotes Recovery after Surgical Repair of Injured Peripheral Nerves.

Injured peripheral nerves regenerate their axons in contrast to those in the central nervous system. Yet, functional recovery after surgical repair is often disappointing. The basis for poor recovery is progressive deterioration with time and distance of the growth capacity of the neurons that lose their contact with targets (chronic axotomy) and the growth support of the chronically denervated Schwann cells (SC) in the distal nerve stumps. Nonetheless, chronically denervated atrophic muscle retains the capacity for reinnervation. Declining electrical activity of motoneurons accompanies the progressive fall in axotomized neuronal and denervated SC expression of regeneration-associated-genes and declining regenerative success. Reduced motoneuronal activity is due to the withdrawal of synaptic contacts from the soma. Exogenous neurotrophic factors that promote nerve regeneration can replace the endogenous factors whose expression declines with time. But the profuse axonal outgrowth they provoke and the difficulties in their delivery hinder their efficacy. Brief (1 h) low-frequency (20 Hz) electrical stimulation (ES) proximal to the injury site promotes the expression of endogenous growth factors and, in turn, dramatically accelerates axon outgrowth and target reinnervation. The latter ES effect has been demonstrated in both rats and humans. A conditioning ES of intact nerve days prior to nerve injury increases axonal outgrowth and regeneration rate. Thereby, this form of ES is amenable for nerve transfer surgeries and end-to-side neurorrhaphies. However, additional surgery for applying the required electrodes may be a hurdle. ES is applicable in all surgeries with excellent outcomes.

Clinical Outcome of the Type A Acute Aortic Dissection Repair Using the "Tailored Stand-Up Collar" Technique.

Achieving a secure anastomosis and complete hemostasis is essential for surgically treating type A acute aortic dissection (TAAAD). This study assessed the clinical feasibility of "tailored stand-up collar (TSC)" technique for constructing the distal stump. We enrolled 68 patients who underwent ascending aortic repair for TAAAD. Patients were categorized according to the technique for distal stump construction: conventional (C) group using only a felt strip (32 cases); post-aortotomy (P) group, with a Hydrofit-felt strip attached after aortotomy (18 cases), and TSC group, where a Hydrofit-felt strip attached during cooling (18 cases). Pre-operative characteristics, procedural profiles, and post-operative outcomes were evaluated. The pre-operative characteristics were identical among the groups. The durations of cardiopulmonary bypass, hemostasis, and surgery were significantly shorter in the P and TSC groups. The duration of open distal in the TSC group (21 min) was significantly shorter than the other two groups. Post-operative additional procedures were not required for the TSC group and their post-operative hospital stay was significantly shorter (47.1% of patients were discharged within 2 weeks). The TSC technique would be practical because of its high reproducibility in terms of ease of use, shorter anastomotic time, and secure hemostasis.

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.

Biological Prosthesis (Hollow 3D-Printed Titanium Custom-Made Prosthesis and Bone Graft) for Humeral Reconstruction in Pediatric Oncologic Patients: Surgical Indications and Results.

This study presents the mid-term outcomes of a novel "biological prosthesis" for pediatric humerus reconstruction after major bone tumor removal. This approach involves a hollow 3D-printed titanium custom-made prosthesis combined with bone grafting. The primary aim was to preserve and revitalize the unaffected autologous proximal or distal humeral stump. Between 2017 and 2021, we treated five pediatric patients (mean age 11.2 years; range 7-17) with humeral bone sarcomas. A one-stage surgical procedure involved tumor resection and implanting a hollow 3D-printed custom-made prosthesis. In two cases, we preserved the proximal humerus; in two, the distal part; and in one, both. Graft materials included homologous bone chips in three cases and free vascularized fibular grafts in two cases. All patients were clinically and radiographically assessed after a mean follow-up of 32.2 months (range of 14-68). No significant complications were observed, and no implant revisions were needed. Osseointegration was evident in all cases within eight months post-surgery; vascular support for the remaining autologous stump was demonstrated in all cases. Our hollow 3D-printed custom-made prosthesis and bone grafting offer the potential for partial or complete articular surface preservation. This approach encourages revascularization of the epiphysis, leading to satisfactory outcomes in humerus reconstruction within the pediatric population.

Quantitative evaluation of rat sciatic nerve degeneration using high-frequency ultrasound

In this study, we evaluated the utility of using high-frequency ultrasound to non-invasively track the degenerative process in a rat model of peripheral nerve injury. Primary analyses explored spatial and temporal changes in quantitative backscatter coefficient (BSC) spectrum-based outcomes and B-mode textural outcomes, using gray level co-occurrence matrices (GLCMs), during the progressive transition from acute to chronic injury. As secondary analyses, correlations among GLCM and BSC spectrum-based parameters were evaluated, and immunohistochemistry were used to suggest a structural basis for ultrasound outcomes. Both mean BSC spectrum-based and mean GLCM-based measures exhibited significant spatial differences across presurgical and 1-month/2-month time points, distal stumps enclosed proximity to the injury site being particularly affected. The two sets of parameters sensitively detected peripheral nerve degeneration at 1-month and 2-month post-injury, with area under the receiver operating charactersitic curve > 0.8 for most parameters. The results also indicated that the many BSC spectrum-based and GLCM-based parameters significantly correlate with each other, and suggested a common structural basis for a diverse set of quantitative ultrasound parameters. The findings of this study suggest that BSC spectrum-based and GLCM-based analysis are promising non-invasive techniques for diagnosing peripheral nerve degeneration.

Abstract 093: Carotid Stump Syndrome: an Insidious Source of Recurrent Ischemic Strokes

Introduction Carotid stump syndrome (CSS) is a paradoxical phenomenon that occurs when there are repeated ischemic events in the carotid vascular territory despite demonstrated occlusion of the ipsilateral internal carotid artery (ICA). It is thought to be caused by turbulent blood flow in the patent stump of the occluded ICA creating microemboli which reach the brain through anastomotic channels and retrograde flow. We present a case of recurrent infarctions in setting of known ipsilateral ICA occlusion, who was diagnosed with carotid stump syndrome. Methods A male veteran in his 60s with a medical history of DVTs on apixaban, PVD, and ischemic stroke with residual right‐sided weakness, presented with worsening right‐sided weakness and difficulty with ambulation. Two months prior to the presentation he was diagnosed with acute infarcts in left frontal, parietal, and temporal lobes due to thromboembolism from left ICA occlusion. On presentation his neurological exam revealed right‐sided hemiparesis. MRI brain showed multiple acute and chronic cortical and subcortical infarcts in the left frontotemporoparietal lobes and lack of flow void in the left distal ICA. To further evaluate the dynamics of blood flow patient underwent a cerebral angiogram which confirmed the diagnosis of complete occlusion of left ICA and demonstrated reconstitution of the intracranial ICA through retrograde filling via the ophthalmic artery and anastomotic branches with the internal maxillary artery (IMax). For secondary prevention he was started on statin and aspirin while his home Apixaban was continued. Surgical and endovascular treatment approaches were discussed but the patient declined any intervention. In his four months follow up clinic visit he had no further concerns of recurrent strokes or new symptoms. Results Carotid stump syndrome is a rare cause of cerebral and retinal ischemia; however, it must be considered in patients with recurrent ischemic strokes and chronic ipsilateral ICA occlusion. Due to the patent proximal, or perhaps in some cases distal, carotid stump, there’s turbulent flow and hence the thrombus formation can occur. Hemodynamic and embolic factors attribute towards the microembolization from the proximal carotid stump through the external carotid artery (ECA), into the facial artery and IMax and their distal branches which anastomose with the ophthalmic artery, causing the emboli to end up in the major branches of the carotid terminus. If a distal stump is symptomatic, then the microemboli can readily end up in the distal ICA branches. In addition to medical management with DAPT or anticoagulation and high intensity statin, our literature review supports endovascular or surgical interventions due to reportedly good outcomes. Interventional approaches may include ECA‐ICA stenting with a covered stent or stent‐assisted coil embolization of the proximal stump. Surgical procedures include an endarterectomy on the ipsilateral ECA or contralateral ICA to increase collateral circulation. ECA‐ICA bypass is another option. Conclusion Carotid stump syndrome is a rare and underrecognized cause of recurrent ischemic strokes, though it is a potentially treatable entity. The therapeutic goals include medical management along with endovascular or surgical treatment whenever possible.

Challenging management of a baby with congenital multiple intestinal atresia, trisomy 18 and extremely low birth weight: a case report

BackgroundExtremely low birth weight (< 1000 g) still influences postsurgical prognosis in the neonatal and infantile periods. Additionally, the life expectancy of neonates with trisomy 18 is extremely poor owing to various comorbidities. Therefore, it takes courage to perform laparotomy for the purpose of treatment of congenital multiple intestinal atresia in a baby with an unpredictable life prognosis.Case presentationFetal ultrasonography revealed cardiac malformation, intestinal dilation, and physical characteristics suggestive of a chromosomal abnormality in this case. The patient was diagnosed with trisomy 18 after birth, with an extremely low birth weight. An atrial septal defect, ventricular septal defect, dilated jejunum, and a very thin collapsed small intestine were found on ultrasonography. With a diagnosis of congenital small intestinal atresia, a challenging laparotomy was done at 3 days of age, with jejunal atresia and multiple distal small intestinal atresia were observed. The jejunal end and distal small intestinal stump were separated into stomas at the wound edge. Hypertrophic pyloric stenosis developed at the age of 3 months and resolved with medication. The patient gained weight (2 kg) by daily stool injection into anal side of the intestine and decompression against poor peritonitis of dilated jejunum using enteral feeding tube for the long period. Finally, we could perform intestinal reconstruction safely and successfully at the age of 9 months.Tracheotomy was performed due to difficulty in extubation associated with chronic lung disease. The patient was discharged at the age of 1 year and 3 months, and no major problems were noted at the age of 2 years.ConclusionsWe treat congenital intestinal atresia in extremely low birth weight infants with severe chromosomal abnormalities and severe cardiac malformations as follows: Stoma creation is performed quickly to avoid deterioration of the patient's hemodynamics. After that, while continuing enteric management, palliative cardiovascular surgery is performed as necessary, and the patient's body weight and intestinal tract status are determined to allow safe intestinal reconstruction.

Faecal diversion remains central in the contemporary management of rectal trauma–Experience from a major trauma centre in South Africa

IntroductionThis paper provides an overview of a single centre's experience with rectal injury over a decade. It hopes to use this data to provide context to our current approach to managing these injuries in the civilian setting. The StudyAll patients with rectal trauma were identified from the Hybrid Electronic Medical Registry (HEMR). ResultsDuring the study period, a total of 88 patients with rectal injuries were admitted to Grey's Hospital in Pietermaritzburg. There were 80 (91 %) males and 8 (9 %) females. The median age was 31 (15–63) years. There were 9 (10 %) blunt mechanisms, 76 (86 %) penetrating mechanisms and 3 (4 %) combined blunt and penetrating mechanisms. Gunshot wounds accounted for the majority of sustained rectal trauma (71 %). There were 57 (65 %) extra-peritoneal injuries, 24 (27 %) intraperitoneal injuries and 7 (8 %) combined injuries. The grade of injury, according to the AAST grading system, was as follows, AAST 1: 16 (18 %), AAST 2: 63 (72 %), AAST 3: 7 (8 %), and AAST 4: 2 (2 %). Pre-sacral drainage and distal rectal washout were not performed. Almost all (55/57) of the extra-peritoneal rectal injuries were managed with proximal diversion (PD). There were five primary repairs (PR) performed in the extra-peritoneal rectal injury cohort. In four of these cases, this was accompanied by a PD. Of the 24 intraperitoneal rectal injuries, 15 underwent PR, of which 11 were performed in conjunction with PD. In total, 20 intraperitoneal rectal injuries underwent PD. All seven combined rectal injuries underwent PD, and three of the combined rectal injuries underwent PR with PD. There was urogenital tract associated morbidity in 8 %, gastrointestinal tract related morbidity in 8 % and septic complications in 11 %. ConclusionRectal trauma is still associated with a high rate of rectal/urogenital and infection related morbidity. Although pre-sacral drainage and distal stump washout have been largely abandoned in civilian practice, faecal diversion currently remains the cornerstone of the management of rectal trauma in our environment. Although there was a low rate of intra-abdominal septic complications in patients who had undergone diversion, this needs to be balanced against the low rate of stoma reversal.

Chronic Achilles Tendon Rupture Reconstruction with Semitendinous Autograft Tendon: A Case Series

Category: Sports; Ankle Introduction/Purpose: Chronic Achilles tendon ruptures is challenging because the tendon ends are usually retracted, and if the gap between the proximal and distal stumps are of more than 6 cms with the ankle in plantarflexion the currently literature shows that semitendinous tendon (ST) autograft reconstruction has satisfactory funcional outcome. The objetive of this study is evaluate the functional outcomes after Achilles tendon reconstruction with ST. Methods: Prospective case series, level IV of evidence, authorized by Ethics Committee of our institution, assessed the clinical outcome of patients submitted to achilles tendon reconstruction between march 2021 and june 2022. The patients were diagnosed by 2 orthopaedic foot and ankle surgeons board certificated and were subjected to the following inclusion criteria: age between 18-60 years, agreeing to participate, with chronic achilles tendon rupture (&gt; 12 weeks) and gap between proximal and distal stump larger than 6cm confirmed by ultrasound with the ankle in plantarflexion position. Demographic data was obtained, including gender, BMI and height and the full ST length was measured intraoperatively. AOFAS Hindfoot Score and Achilles Tendon Total Rupture Score (ATRS) were evaluated pre and postoperatively (last evaluation). Results: 20 patients were included, with medium age of 45 years old (range 23 to 64 )and medium gap of 6,3 cm (range 6 to 6,6). (Table 1). The pre and postoperative AOFAS-hindfoot was 71 (range 48 to 83) and 89 (range 81 to 97), respectively, and the pre and posoperative ATRS was 33 (range 30 to 47) and 88 (range 86 to 92), respectively, both with statistic significance. The medium lenght of the ST from the posterior approach was 26.3 cm and the medium VAS for pain in the ST incision was 1. There were 2 cases of superficial infection treated with oral antibiotics for 7 days of full resolution and 1 case of superficial dehiscence treated with wound dressing. Conclusion: The surgical reconstruction of AT using ST harvested from posterior approach is a safe and reliable method for treatment of chronic AT ruptures with a gap larger than 6 cm, with a significant improvement in funcional scores and just 15% of minor complications.

Simultaneous Reconstruction of Smiling Eye Using V-Shaped Long Latissimus Dorsi Muscle Transfer in Patients with Flaccid Facial Paralysis.

Various neurovascular free muscle transfers for smile reconstruction in patients with facial paralysis have been reported. However, these methods focused on perioral smiling rather than eye smiling. Although the lower eyelid does not contribute significantly to eyelid closure, dynamic reanimation of the upward movement of the lower eyelid with bulging of the malar region during smiling is important in smile reconstruction. The authors present a novel procedure for smiling eye and perioral smiling. The V-shaped latissimus dorsi muscle flap containing the descending branch (DB) of the thoracodorsal nerve (TDN) was used. Muscle A (15 to 17 cm), which is located along the main trunk of the DB, is much longer than muscle B (10 to 12 cm), which is along the branch of DB. A distal stump of the TDN involved in muscle B was prepared. The true trunk and distal stump of the TDN were sutured to the contralateral facial and ipsilateral masseteric nerves, respectively. The central region of muscle A was positioned at the lateral part of the lower eyelid; the distal end of long muscle A was affixed to the temporal region, which enabled periocular movements and narrowing of the palpebral fissures alongside perioral smiling when muscle A contracted. Nine patients with complete flaccid facial paralysis were treated. All patients attained muscle contraction induced by the ipsilateral masseteric and contralateral facial nerves. The smiling eye appearance was observed in 7 of 9 patients. This procedure simultaneously improves paralytic ectropion at rest and aids eyelid closure and enables early voluntary smile and a later spontaneous smile.

A pilot prospective cohort study using experimental quantification of early peripheral nerve regeneration with high-frequency three-dimensional tomographic ultrasound (HFtUS)

Quantification of peripheral nerve regeneration after injury relies upon subjective outcome measures or electrophysiology assessments requiring fully regenerated neurons. Nerve surgeons and researchers lack objective, quantifiable information on the site of surgical repair and regenerative front. To address this need, we developed a quantifiable, visual, clinically available measure of early peripheral nerve regeneration using high-frequency, three-dimensional, tomographic ultrasound (HFtUS). We conducted a prospective, longitudinal study of adult patients with ulnar and/or median nerve injury of the arm undergoing direct epineurial repair within 5 days of injury. Assessment of morphology, volumetric and 3D grey-scale quantification of cross-sectional views were made at baseline up to 15 months post-surgery. Sensory and motor clinical outcome measures and patient reported outcome measures (PROMs) were recorded. Five participants were recruited to the study. Our data demonstrated grey-scale values (an indication of axonal density) increased in distal stumps within 2–4 months after repair, returning to normal as regeneration completed (4–6 months) with concomitant reduction in intraneural volume as surgical oedema resolved. Two patients with abnormal regeneration were characterized by increased intraneural volume and minimal grey-scale change. HFtUS may quantify early peripheral nerve regeneration offering a window of opportunity for surgical intervention where early abnormal regeneration is detected.

Pre-operative factors associated with the development of distal ureteral stump syndrome after upper pole heminephrectomy

For children with duplex systems and severe hydroureteronephrosis of the upper pole, heminephrectomy is one of many suitable treatments, particularly if there is no associated lower pole reflux. Distal ureteral stump syndrome (DSS) is a very difficult complication and manifests as stump empyema, urinary tract infection and/or vulvar discharge and can occur months to years later in 10-20 percent of patients. Secondary distal ureterectomy is an extremely difficult surgery due to inflammation and adhesions. To avoid DSS, distal ureterectomy at the time of heminephrectomy can be performed concurrently but carries a risk of lower pole ureter devascularization and injury. Current literature on DSS has shown associations with subtotal ureterectomy or long ureteral stumps. We hypothesized that there may be preoperative variables prior to heminephrectomy that are associated with the development of DSS. Identify pre-operative risk factors for the development of DSS in pediatric patients who underwent upper pole heminephrectomy for duplex kidneys. Retrospective analysis of pediatric patients who underwent upper pole heminephrectomy at single, academic institution from 1999 to 2021. Pre-operative patient age, gender, history, imaging, and lab results were extracted from patient charts to assess for factors that may predict the development of DSS. Patient groups with and without DSS were compared using Fischer's Exact Test. Five (14%) of 36 patients developed DSS and required secondary distal ureterectomy at a median time of 22 months (IQR 6-27) after heminephrectomy. The presence of ureteral debris (80% of DSS) on preoperative ultrasound (p<0.001), reflux into the upper pole (p=0.005), and mucus discharge (100% of DSS) (p<0.001) prior to surgery were found to be significantly associated with those who developed DSS, compared to those who did not. These three pre-operative factors had high specificity (97-100%) and negative predictive value (94-97%). Substantial experience has shown that less than 20% of patients benefit from distal ureterectomy during upper heminephrectomy. Whether using an open or laparoscopic approach, selection of at-risk patients should lower operative time and avoid injury and devascularization of the lower pole ureter for most patients. The presence or absence of ureteral debris, mucus discharge and/or upper pole reflux prior to heminephrectomy may be useful guides in selecting which patients would benefit from concurrent distal ureterectomy and conversely which patients may safely avoid the additional dissection.

Lymphatic reconstruction with vascularized lymph vessel flap: lymph-interpositional-flap transfer

Lymph node transfer (LNT) and lymphatic anastomosis are popular reconstructive surgeries in managing lymphedema. However, lymphatic anastomosis requires the operator to be adept at super microsurgery, and LNT has significant donor-site lymphedema risks. To address these drawbacks, lymph-interpositional-flap transfer (LIFT), a novel lymphatic reconstruction method that does not require lymph node transfers or supermicrosurgical techniques, has been introduced. Lymph circulation after tissue replantation and free flap transfer was evaluated using indocyanine green (ICG) lymphography. Postoperative ICG lymphography showed linear to linear lymphatic reconnection between an amputee/flap and a recipient site in cases where the stumps of the lymph vessels were only approximated. This was a frequent phenomenon observed in replantation cases and some free tissue transfers. Based on these results, we developed a new lymphatic reconstruction using a flap designed to include the collecting lymph vessels for bridging a lymphatic gap. ICG is injected at the peripheries of donor sites or the distal boundaries of the lymphosome where the recipient site resides in. This allows us to visualize the axial lymphatic pathways. When LIFT is used to reconstruct a soft tissue defect, ICG is also injected at the proximal edge of it to visualize proximal lymph flows. The LIFT flap is designed to include lymphatic channels seen on pre-operative ICG lymphography. As these collecting lymph vessels reside deep in the superficial fascia, the flap is elevated with the deep fat intact. Intra-operative ICG lymphography is utilized to identify the proximal and distal lymphatic stumps on the flap, and absorbable sutures are used to tag these stumps for ease of recognition during the flap inset. LIFT is indicated for soft tissue defects in major lymphosomes, resulting in a significant lymphatic gap. The advantage of the LIFT technique is the ability to perform simultaneous soft tissue and lymphatic reconstruction. LIFT can also be applied in established lymphedema and elephantiasis.

Ruptured vertebrobasilar junction aneurysm supplied by reversed flow from the anterior spinal artery: Illustrative case report.

In patients with vertebral artery (VA) occlusion, spontaneous flow reversal may occur in the anterior spinal artery (ASA) as a source of compensatory supply to the posterior circulation. Turbulent flow and increased flux through these small arteries may predispose to luminal damage and intracranial aneurysm formation. We report a novel case of a ruptured ASA-VA junction aneurysm in a patient with chronic bilateral VA occlusion, successfully treated with endovascular embolization. A 62-year-old female with uncontrolled hypertension presented with acute-onset headache, emesis, neck stiffness, and decreased level of consciousness. Head computed tomography demonstrated diffuse cisternal subarachnoid hemorrhage with intraventricular extension and ventriculomegaly. Computed tomography angiography showed left VA atresia and chronic right VA occlusion just distal to the posterior inferior cerebellar artery origin, as well as a complex, bilobed aneurysm at the ASA-VA junction. Angiography demonstrated flow reversal from the ASA into the distal stump of the occluded right VA, which in turn filled the aneurysm. Of note, the patient's posterior circulation was predominantly supplied by the dilated ASA, and associated collaterals from ASA and right VA stump. The aneurysm was accessed and embolized using superselective microcatheterization over a soft microguidewire through the right cervical VA perforators supplying retrograde flow into and through the ASA. ASA-VA aneurysms are exceedingly rare, and generally associated with atypical flow dynamics. Dynamic treatment strategies may be needed, especially in the setting of subarachnoid hemorrhage.

Local Administration of Minocycline Improves Nerve Regeneration in Two Rat Nerve Injury Models.

Peripheral nerve injuries are quite common and often require a surgical intervention. However, even after surgery, patients do not often regain satisfactory sensory and motor functions. This, in turn, results in a heavy socioeconomic burden. To some extent, neurons can regenerate from the proximal nerve stump and try to reconnect to the distal stump. However, this regenerating capacity is limited, and depending on the type and size of peripheral nerve injury, this process may not lead to a positive outcome. To date, no pharmacological approach has been used to improve nerve regeneration following repair surgery. We elected to investigate the effects of local delivery of minocycline on nerve regeneration. This molecule has been studied in the central nervous system and was shown to improve the outcome in many disease models. In this study, we first tested the effects of minocycline on SCL 4.1/F7 Schwann cells in vitro and on sciatic nerve explants. We specifically focused on the Schwann cell repair phenotype, as these cells play a central role in orchestrating nerve regeneration. Finally, we delivered minocycline locally in two different rat models of nerve injury, a sciatic nerve transection and a sciatic nerve autograft, demonstrating the capacity of local minocycline treatment to improve nerve regeneration.

Clinical evaluation of the perception of post-trauma paresthesia in the mandible, using a biomimetic material: A preliminary study in humans

There is a great effort from numerous research groups in the development of materials and therapeutic strategies for the functional recovery of patients who have suffered peripheral nerve injuries (PNI). In an article in vivo, the formation of a nerve bridge was observed, reconnecting the distal and proximal stumps, in the sciatic nerve of rats, indicating the effective participation of the biomaterial in the recovery of peripheral nerve injuries. For the current pilot study, 15 cases of multiple fractures of the mandible, with involvement of the inferior alveolar nerve (IAN) were selected and studied: JC (control cases) n = 6 with conventional treatment, and JT (treated cases) n = 9, with the use of biomimetic biomaterial. The evaluation of the return to sensitivity was measured through a self-assessment, where the patients assigned scores from 0 to 10, where zero (0) represented the complete absence of sensitivity and ten (10) the normality of the perception of local sensitivity. Patients were evaluated from the preoperative period to the 360th day. The statistical results obtained by the t-Student, Shapiro-Wilk normality and non-parametric One-Way ANOVA tests indicated statistically significant differences (p < 0.005; 0.005 e 0.5 respectively), between the two treatments, which were reflected in the clinical results observed, we also calculate the size of the effect represented by ϵ2, calculated by Cohen's d. The results indicate a great difference between the treatments performed,ϵ2 = 1.00. In the 6 cases followed up in the JC group, four remained with a significant deficit until the end of the evaluations and two indicated the remission of the lack of sensitivity in this period. In the JT group, in 28 days, all cases indicated complete remission of the lack of sensitivity with healing concentration. In one of the cases where there was a complete rupture of the mental nerve, the (score-10) was observed in 60 days. The observed results indicate the existence of a statistical significance between the groups and an important relationship when using the biomimetic biomaterial during the recovery of the perception of sensitivity in polytraumatized patients, compatible with the results observed in laboratory animals, which may indicate its clinical feasibility in the reduction of sequelae in PNI.

A comparison of characteristics and outcomes of operative treatment for Achilles tendon sleeve avulsion in older versus younger patients.

Achilles tendon sleeve avulsion (ATSA) is a rare injury that often results from pre-existing insertional Achilles tendinopathy and occurs when a tendon avulses from the insertion as a continuous sleeve. To date, outcomes of operative treatment for ATSA in older patients have not been reported. Therefore, this study aims to compare the characteristics and outcomes of Achilles tendon (AT) reattachment with or without tendon lengthening for ATSA between older and younger patients. This study enrolled 25 consecutive patients who underwent operative treatment following a diagnosis of ATSA between January 2006 and June 2020. The inclusion criterion was a minimum follow-up duration of one year. The enrolled patients were divided into two groups according to their age at operation: ≥ 65years (group 1, 13 patients) and < 65years (group 2, 12 patients). AT reattachment was performed in all patients using two 5.0-mm suture anchors after an inflamed distal stump resection in the 30° plantar-flexed ankle position. The degree of active dorsiflexion and plantar flexion, mean visual analog scale score, and Victorian Institute of Sports Assessment-Achilles scores at the final follow-up were not significantly different between the two groups (P > 0.05 each). The rate of satisfactory clinical outcomes (defined as fair or greater) was 84.6% and 91.7% in groups 1 and 2, respectively. We observed that comparable clinical outcomes could be achieved after AT reattachment with or without lengthening for ATSA between older and younger patients.

Endoscopically Assisted Percutaneous Harvesting of the Flexor Hallucis Tendon in Zone 2: An Anatomical Study.

Flexor hallucis longus (FHL) transfer is a well-established method for treating chronic Achilles tendon ruptures and tendinopathy. Harvesting of the FHL tendon in zone 2 results in greater length but is also associated with an increased risk of injury to the medial plantar nerve and requires an additional plantar incision. Because of the anatomic proximity of the FHL tendon to the tibial neurovascular bundle in zone 2, the purpose of this study was to investigate the risk of vascular or nerve injury with arthroscopic assisted percutaneous tenotomy in zone 2 of the FHL tendon. Endoscopically assisted percutaneous FHL transfer was performed on 10 right lower extremities from 10 cadaveric human specimens. The FHL tendon lengths and the relationship between FHL tendon and the tibial neurovascular bundle at zone 2 was analyzed. We observed a complete transection of the medial plantar nerve in 1 case (10%). The mean length of the FHL tendon was 54.7 ± 9.5 mm and the mean distance from the distal stump of the FHL tendon to local neurovascular structures was 1.3 ± 0.7 mm. There is a risk of neurovascular injury after endoscopic FHL tenotomy in zone 2. The tenotomy site is within 2 mm of the local neurovascular structures in the majority of cases. The additional length gained from this technique is unlikely to be required for the majority of FHL tendon transfer procedures. If additional length is needed, we would recommend the use of intraoperative ultrasonography or a mini-open approach to minimize injury risk. Level V, expert opinion.

Novel reinforcement technique using pre-glued felt strip with Hydrofit® for a distal anastomotic site in acute type A aortic dissection.

In the surgical treatment of acute type A aortic dissection, performing the anastomosis in the dissected aorta is technically challenging due to the fragility of the dissected aortic wall. This study describes the reinforcement technique for the distal anastomotic site, using pre-glued felt strips with Hydrofit®. No intraoperative bleeding occurred at the anastomosis site of the distal anastomosis stump. Postoperative computed tomography revealed no new distal anastomotic entry. This technique is recommended for managing acute type A aortic dissection during distal aortic reinforcement.