An optimized framework for prediagnosis of diabetic retinopathy using HHO-CBL model

BACKGROUND

Diabetic Retinopathy (DR) is a widespread intense stage of diabetes mellitus that causes vision-effecting anomalies in the retina. It is a medical health condition on the strength of fluctuating glucose level in the blood that can result in vision loss in case of severity.

OBJECTIVE

As a result, early detection and treatment with DR is the most significant task which will tremendously reduce the likelihood of vision impairment and is still a difficult challenge. Many conventional methods fail to detect primary causes of formation of Microaneurysms, that are used to determine the Prediagnosis of DR.

METHOD

To overcome this challenge, the proposed model incorporates Harris Hawk Optimization with CNN-Bi-LSTM (HHO-CBL) to extract the features. The Prediagnosis of DR has been achieved through this model by spotting saccular dilations, hyaline like material in the capillary aneurysm wall, kinking of vessels since these are the indications for the creation of microaneurysms that are spotted in the blood vessel of the retina. The recommended model is also used to automatically detect DR and its progression in many phases. Furthermore, in order to identify the severity of DR retina, we used a benchmark Kaggle APTOS dataset to train the HHO-CBL model.

RESULTS

Experimental results reveal that this model obtains the best classification accuracy of 96.4 % for an early diagnosis and 98.8 % for a five-degree classification. In addition to those results, a comparison with previously carried out studies has also shown that this model provides a promising solution for a successful Prediagnosis of DR and its staging.

CONCLUSIONS

In the current research, an innovative HHO-CBL was developed for identifying the primary causes that lead to the formation of microaneurysms and diagnosing all five grades of DR. According to the acquired results presented through the evaluation performance metrics indicates that the pre-early diagnosis and five grade classification using feature embedding technique outperformed the other prevailing approaches (Tab. 4, Fig. 10, Ref. 31).

Reshaping Covalent Nanowires by Exploiting an Unexpected Plasticity Mediated by Deformation Twinning

Nanowires (NWs) are among the most studied nanostructures as they have numerous promising applications thanks to their various unique properties. Furthermore, the properties of NWs can be tailored during synthesis by introducing structural defects such as nano-twins, periodic polytypes, and kinks, i.e., abrupt changes in their axial direction. Here, this work reports for the first time the postsynthesis formation of such defects, achieved by exploiting a peculiar plasticity that may occur in nanosized covalent materials. Specifically, in this work the authors found that single-crystal CuO NWs can form double kinks when subjected to external mechanical loading. Both the microscopy and atomistic modeling suggest that deformation-induced twinning along the( 1 ¯ 10 ) $( {\bar{1}10} )$ plane is the mechanism behind this effect. In a single case the authors are able to unkink a NW back to its initial straight profile, indicating the possibility of reversible plasticity in CuO NWs, which is supported by the atomistic simulations. The phenomenon reported here provides novel insights into the mechanisms of plastic deformation in covalent NWs and offers potential avenues for developing techniques to customize the shape of NWs postsynthesis and introduce new functionalities.

Endovascular straightening of the internal carotid artery during mechanical thrombectomy: The "tightrope technique"

Mechanical thrombectomy is a standard treatment for acute stroke, but it can be technically challenging in elderly patients with difficult vascular anatomy. To overcome this issue, we propose a new endovascular approach called the "tightrope" technique. This technique uses a stiff guidewire and a standard angiographic catheter to straighten the internal carotid artery (ICA) tortuosity, allowing the guiding catheter to be positioned next to the intracranial level. We retrospectively evaluated all the procedures in which the "tightrope" technique was used. This approach involves advancing a 0.035″ Advantage stiff guidewire and a standard 4 Fr angiographic catheter through the vascular tortuosity. The catheter is twisted over the guide wire in a clockwise direction, gaining tension that gradually straightens the vascular axis, allowing the guiding catheter to pass up to the distal ICA. Between June 2022 and March 2023, we successfully performed consecutive mechanical thrombectomy procedures using the tightrope technique in 11 patients with highly tortuous ICA segments. In all cases, we were able to safely advance the catheter system up to the distal cervical ICA. Although our study included a small cohort of patients, the "tightrope" technique proved to be successful in all patients, allowing for safe advancement of the guiding catheter toward extremely tortuous anatomy. However, further validation in a larger patient population is necessary to determine the technique's effectiveness and safety profile.

Patient-specific stent for hemolytic anemia due to a kinked ascending aortic graft

Hemolytic anemia after thoracic aortic surgery is rare. A 69-year-old female patient, who underwent ascending aorta replacement for acute type A aortic dissection 7 years ago, was transferred from another hospital due to hemolytic anemia necessitating regular blood transfusions. After engaging in interdisciplinary discussions, we ruled out alternative medical diagnoses and treatments, ultimately identifying the kinked aortic graft as the primary cause of hemolysis. Due to the patient's comorbidity, it was deemed high-risk to perform a redo thoracic aorta surgery for the replacement of the kinked aortic graft. Therefore, we decided to insert a patient-specific bare-metal stent into the kinked aortic graft to alleviate the kinking and promote improvement in hemolysis. We decided to perform the stent procedure under local anesthesia. The bare-metal stent was designed to be approximately 15% larger than the size of the pre-existing kinked aortic graft. A stent measuring 32 mm × 80 mm was successfully inserted and ballooned within the patient's ascending aortic graft. As a result, the patient's hemolytic condition showed gradual improvement over time. In this way, we aim to share our experience of inserting a patient-specific bare-metal stent under local anesthesia in patients who exhibit mechanical hemolysis due to a kinked aortic graft, especially when redo surgery is considered high-risk.

A Study of the Association Between Carotid Artery Curvature and Intracranial Aneurysms

BACKGROUND

Carotid artery curvature is considered a sign of a weak vessel wall, and we hypothesize that a weak vascular wall under the effect of hemodynamics may cause intracranial aneurysms.

MATERIALS AND METHODS

The general data of 534 patients with aneurysms and 473 control patients were retrospectively analyzed in a case-control study. Carotid artery curvature was characterized as none, tortuosity, kinking, and coiling by computed tomography angiography images. Univariate analysis was performed to determine the degree of carotid artery tortuosity and to analyze the general data between the aneurysm group and the control group, and then, multivariate statistical logistic regression analysis was used to analyze the statistical significance of the univariate analysis. Finally, the correlation between aneurysm-related features and carotid artery curvature was analyzed.

RESULTS

Univariate analysis showed that kinking was significantly related to the occurrence of intracranial aneurysms ( P =0.009). The results of multivariate regression analysis showed that kinking was an independent risk factor for the occurrence of aneurysms (odds ratio: 1.942; 95% confidence interval: 1.387-2.720 for model 1; odds ratio: 1.995; 95% confidence interval: 1.419-2.805 for model 2). In the analysis of the correlation between the characteristics of intracranial aneurysms and the curvature of the internal carotid artery, there was no correlation between the curvature of the internal carotid artery and the size, location or number of aneurysms, or whether the intracranial aneurysm was ruptured.

CONCLUSION

Intracranial aneurysms are associated with carotid artery curvature. Kinking of the internal carotid artery may indicate a higher risk for aneurysm formation.

Dolichoarteriopathy of Common Carotid Artery: An Unusual Entity

Dolichoarterial disease of the carotid arteries refers to elongated arteries with tortuous, coiling, and kinking anatomy. This morphology is usually met in the elderly and not associated with atherosclerotic risk factors. Current practice reserves surgical correction only in symptomatic patients. Significant tortuosity index may be associated with stroke and poses extra difficulties to the endovascular passage of guidewires and catheters for the treatment of extra- and intracranial vascular lesions. This article presents a typical case of bilateral dolichoarteriopathy of the common carotid artery and stresses the need for further categorization of the particular morphology based on modern angiography techniques and three-dimensional reconstruction software.

Use of absorbable hemostat bolster for prevention of donor renal artery kinking in kidney transplant

Transplant renal artery stenosis due to mechanical kinking is a rare but significant complication in kidney transplantation that can lead to graft dysfunction due to graft hypoperfusion, delayed graft function, or even global kidney infarction. When detected during surgery, re-anastomosis is usually performed after re-clamping, which inevitably prolongs the warm ischemia time, and increases the possibility of primary graft non-function. In this report, we describe a novel, noninvasive surgical technique whereby the donor renal artery is padded with absorbable hemostatic material (i.e., Surgicel) bolster, placed below the middle third of the renal artery in recipients who were found to have mechanical kinking during the implantation procedure. The bolster technique was used in 12 kidney transplant recipients who were found to have kinking of the donor artery during the primary surgery. After pillowing the renal artery with absorbable hemostatic bolster, no residual kinking was observed intra-operatively, and good allograft perfusion was confirmed with no Doppler ultrasound evidence of renal artery stenosis confirmed at 1 week, 1 month, and 1 year after transplantation.

Association between kinking of the cervical carotid or vertebral artery and ischemic stroke/TIA

Introduction

Kinking of the cervical carotid or vertebral artery is a common structural abnormality in patients with cerebrovascular disease. However, there is no consensus about the relationship between kinking and ischemic stroke/TIA. We aim to determine the effect of arterial kinking on ischemic stroke/TIA.

Methods

A retrospective study was performed on patients who underwent cerebral angiography with DSA between January 2014 and December 2018. Demographic information and comorbidities were recorded. Each anatomical circulation system was defined as an observation unit. Kinking and stenosis of each circulation unit were recorded. Ischemia stroke or TIA within 6 months and its location were assessed as an outcome. Logistic regression with a generalized estimating equation approach was used for the analysis.

Results

A total of 1,062 patients (mean age 57.9 ± 14.5 years, 740 males and 322 females) were included in the study. Of the patients, 369 (35%) had kinking and 771 (73%) had ischemic stroke/TIA. There were 110 left anterior, 90 right anterior, and 308 posterior circulation units, among which 343 had mild, 160 had moderate, and 243 had severe kinking. Multivariate regression analysis showed that ischemic stroke/TIA was associated with severe kinking (OR 1.39, 95% CI 1.03-1.88, P = 0.03). Posterior circulation was more vulnerable to acute ischemia than left anterior and right anterior circulation (OR 3.58, 95% CI 2.81-4.56, P < 0.0001).

Conclusion

Severe kinking of the cervical carotid or vertebral artery may be associated with a higher risk of ischemic stroke/TIA, especially when the kinking is located in the posterior circulation.

Kinking of Frozen Elephant Trunk Hybrid Prostheses: Incidence, Mechanism, and Management

Introduction

Kinking of the Frozen Elephant Trunk (FET) stent graft is one of the most devastating complications of the FET procedure. It can present post-operatively with reduced arterial pressures in the lower limbs and intermittent claudication. However, it can also be visualized intra-operatively by the surgeons. Unresolved kinking of the stent graft can result in intraluminal thrombus formation and subsequent multi-organ septic emboli.

Aims

The main scope of this review is to collate, summarize and present all the evidence in the literature on kinking of FET stent grafts.

Methods

We carried out a comprehensive literature search on multiple electronic databases including PubMed, EMBASE, Ovid, and Scopus to collate all research evidence on the incidence, mechanism, and management of FET graft kinking.

Results

Incidence of kinking is variable, ranging from 0% to 8% in the literature, with varying rates associated with each stent graft type. The Thoraflex Hybrid^TM prosthesis seemed to be the most commonly used and superior graft, and out of all the 15 cases of kinking reported in the literature, 5 (33.3%) were associated with just the Frozenix graft which had the highest incidence. There are multiple theories regarding the mechanism of kinking, including the direction of blood flow, the length of the stent grafts used, and the position of the prosthesis in relation to the flexure of the aorta. Multiple reparative management techniques have been suggested in the literature and include total endovascular repair, open repair, balloon dilatation, and deploying a second stent graft.

Conclusion

Graft kinking is one of the most critical complications of the FET technique. Its life-threatening sequelae warrant appropriate follow-up of these patients post-operatively, in addition to time management if kinking is suspected. Given the limited evidence in the literature, future studies should incorporate graft kinking into their outcomes reporting.

Abnormal torsion and helical flow patterns of the neo-aorta in hypoplastic left heart syndrome assessed with 4D-flow MRI

BACKGROUND

The Norwood procedure is the first stage of correction for patients with hypoplastic left heart syndrome (HLHS) and may lead to an abnormal neoaortic anatomy. We prospectively studied the neoaorta's fluid dynamics and the abnormal twist of the neoaorta by MRI examinations of HLHS patients in Fontan circulation. This study for the first time investigates the hypothesis that the neoaorta twist is associated with increased helical flow patterns, which may lead to an increased workload for the systemic right ventricle (RV) and ultimately to RV hypertrophy.

METHODS

A group of forty-two HLHS patients with a median age of 4.9 (2.9-17.0) years, at NYHA I was studied along with a control group of eleven subjects with healthy hearts and a median age of 12.1 (4.0-41.6). All subjects underwent MRI of the thoracic aorta including ECG-gated 2D balanced SSFP cine for an axial slice stack and 4D-flow MRI for a sagittal volume slab covering the thoracic aorta. The twist of the neoaortic arch was quantified by the effective geometric torsion, defined as the product of curvature and geometric torsion. Fluid dynamics and geometry in the neoaorta, including the flow helicity index, were evaluated using an in-house analysis software (MeVisLab-based). Myocardial mass of the systemic ventricle at end-diastole was estimated by planimetry of the short-axis stack.

RESULTS

Compared to the control group, the neoaorta in the HLHS patients shows an increased twist (P=0.04) and higher peak helicity density (P=0.03). The maximum helicity density was correlated with maximum effective torsion of the ascending neoaorta (P<0.001). The degree of maximum twist correlated with the increase in RV myocardial mass (P<0.01).

CONCLUSIONS

This study shows that the abnormal twist of the neoaortic arch in HLHS patients is associated with abnormal helical flow patterns, which may contribute to increased RV afterload and may adversely affect the systemic RV by stimulation of myocardial hypertrophy. These findings suggest that further improvements of surgical aortic reconstruction, guided by insights from 4D-flow MRI, could lead to better neoaortic fluid dynamics in patients with HLHS.

A Pseudocoarctation of the Aorta With a Left Subclavian Artery Aneurysm, A Case Report and A Review of the Literature

Here we present a 47-year-old male diagnosed with a pseudocoarctation of the aorta and a funnel-like subclavian artery aneurysm with a large orifice and severe aortic valve insufficiency. The patient underwent a two-stage repair for both pathologies. After an aortic valve replacement, postcardiotomy pericardial effusion occurred and was medically managed. Six months later, the patient underwent a distal arcus aorta and subclavian artery replacement with a left posterolateral thoracotomy as the second stage. Due to the strict adhesions, pulmonary veins were not cannulated and an extracorporeal bypass between the pulmonary artery and femoral artery was used for distal body perfusion. The coincidence of subclavian aneurysms and a pseudocoarctation of the aorta is rare and a literature review was performed to identify treatment options for this pathology.

Symptomatic internal carotid artery dissection and kinking in a patient with fibromuscular dysplasia

Isolated dissection of the internal carotid artery (ICA) is rare in young patients and is a cause for strong suspicion of fibromuscular dysplasia (FMD), especially when associated with artery elongation and tortuosity. The natural history of cerebrovascular FMD is unknown and management of symptomatic patients can be challenging. We report the case of a 44-year-old female patient with a history of transient ischemic attack in the absence of cardiovascular risk factors, associated with an isolated left ICA dissection and kinking. Carotid duplex ultrasound confirmed the diagnosis of dissection and demonstrated severe stenosis of the left ICA. The patient underwent surgical repair and histopathological evaluation confirmed the diagnosis of FMD with dissection. An autogenous great saphenous vein bypass was performed and the patient had an uneventful recovery. Cervical carotid artery dissection can be related to underlying arterial pathologies such as FMD, and the presence of ICA tortuosity highlights certain peculiarities for optimal management, which might be surgical.

Surgical treatment of outflow graft kinking complicated by external obstruction with a fibrin mass in a patient with LVAD

BACKGROUND

Outflow graft (OG) obstruction is a dangerous complication that may occur for various reasons after left ventricular assist device (LVAD) implantation.

CASE SUMMARY

We describe the case of a 51-year-old patient on LVAD support who developed significant OG kinking and external OG obstruction due to a fibrin mass causing severe stenosis. Both the OG kinking and external obstruction were eliminated via a left lateral thoracotomy.

Bilateral carotid neo-bifurcation by symptomatic elongation of the common and internal carotid artery

A 53-year-old female patient was admitted to our clinic with neurological and ophthalmological symptoms and resistant arterial hypertension. After two-stage operation including bilateral carotid resection and carotid neo-bifurcation creation, the blood flow through the vascular regions with abnormal hemodynamics returned to normal and the symptoms of the patient resolved completely.

Revisional Surgery: Aphagia After Gastric Bypass

Background: Gastric bypass is one of the most widely performed bariatric procedures worldwide and continues to be the gold standard in obese patients with metabolic disorders.¹ Regarding the complications, these can appear early or late, the most frequent of the latter being anastomosis stenosis, especially the gastrojejunal (G-J) stenosis. The first treatment option in stenosis is the endoscopic approach, but in cases wherein it fails or the diagnosis is kinking, revisional surgery should be performed. Methods: We describe the technique, step by step, we use to perform a very complex revisional surgery in a patient with aphagia after gastric bypass. Results: This is the case of a 38-year-old female patient who underwent laparoscopic adjustable gastric band in 2011; due to her poor tolerance, a laparoscopic gastric bypass was done. She began with vomiting and gastroesophageal reflux with remarkable symptoms. Diagnosis of stenosis of the jejunojejunal anastomosis of the Roux-en-Y was made and two surgeries were done to treat it. Later the patient referred aphagia and a kink of the gastrojejunal (G-J) anastomosis were observed in the gastrointestinal series. We decided to do a revisional surgery and we describe it step by step in this article. Conclusion: The G-J anastomosis stenosis is the most frequent late complication. Also kinking has to be considered strongly when aphagia or symptoms of obstruction are present. If endoscopic treatment for stenosis or cases of kinking is unsuccessful and fails, then revisional surgery should be considered.

Computational simulations of the helical buckling behavior of blood vessels

Tortuous vessels are often observed in vivo and could hinder or even disrupt blood flow to distal organs. Besides genetic and biological factors, the in vivo mechanical loading seems to play a role in the formation of tortuous vessels, but the mechanism for formation of helical vessel shape remains unclear. Accordingly, the aim of this study was to investigate the biomechanical loads that trigger the occurrence of helical buckling in blood vessels using finite element analysis. Porcine carotid arteries were modeled as thick-walled cylindrical tubes using generalized Fung and Holzapfel-Gasser-Ogden constitutive models. Physiological loadings, including axial tension, lumen pressure, and axial torque, were applied. Simulations of various geometric dimensions, different constitutive models and at various levels of axial stretch ratios, lumen pressures, and twist angles were performed to identify the mechanical factors that determine the helical stability. Our results demonstrated that axial torsion can cause wringing (twist buckling) that leads to kinking or helical coiling and even looping and winding. The specific buckling patterns depend on the combination of lumen pressure, axial torque, axial tension, and the dimensions of the vessels. This study elucidates the mechanism of how blood vessels buckle under various mechanical loads and how complex mechanical loads yield helical buckling.

Comparison of Analytical Approaches Predicting the Compressive Strength of Fibre Reinforced Polymers

Common analytical models to predict the unidirectional compressive strength of fibre reinforced polymers are analysed in terms of their accuracy. Several tests were performed to determine parameters for the models and the compressive strength of carbon fibre reinforced polymer (CFRP) and glass fibre reinforced polymer (GFRP). The analytical models are validated for composites with glass and carbon fibres by using the same epoxy matrix system in order to examine whether different fibre types are taken into account. The variation in fibre diameter is smaller for CFRP. The experimental results show that CFRP has about 50% higher compressive strength than GFRP. The models exhibit significantly different results. In general, the analytical models are more precise for CFRP. Only one fibre kinking model's prediction is in good agreement with the experimental results. This is in contrast to previous findings, where a combined modes model achieves the best prediction accuracy. However, in the original form, the combined modes model is not able to predict the compressive strength for GFRP and was adapted to address this issue. The fibre volume fraction is found to determine the dominating failure mechanisms under compression and thus has a high influence on the prediction accuracy of the various models.

Malfunction of a central venous multilumen access catheter caused by kinking: A case report

RATIONALE

A multilumen access catheter (MAC) is a large-bore catheter that prevents kinking or collapsing. Misplacement is a frequently reported complication.

PATIENT CONCERNS

A 59-year-old man who was diagnosed with a hemoperitoneum due to a liver laceration after a fall.

DIAGNOSIS

After catheterization, we were able to aspirate blood through the 9 Fr, but not the 12-gauge line. Thus, we assumed that the catheter was misplaced. Nevertheless, ultrasonographic findings did not reveal the reason for the malfunction. We found kinking in the distal part of the catheter after removing it.

INTERVENTION

The MAC was removed soon after stopping the active bleeding.

OUTCOMES

A hemihepatectomy was successfully performed, and the patient was transferred to the intensive care unit.

LESSONS

Anesthesiologists should consider kinking of large-bore catheters, including MACs.

Ventilatory Management During Intraoperative Airway Obstruction due to Endotracheal Tube Kinking

We present a case of polyvinyl chloride (PVC) endotracheal (ET) tube kinking and discuss the airway pressure changes, implications, and ventilation-based methods to functionally remedy the situation. The kink developed in the intraoral portion of an 8.5-cm PVC ET tube in a patient undergoing T3-T5 laminectomy in the prone position, heralded by a sudden increase in peak airway pressure. The kink was confirmed by attempted intratubal suction. Adequate ventilation was achieved with conversion to pressure control (PC) mode with an inspiratory-expiratory time (I:E) ratio of 1:1. An experiment was conducted using 8.5-cm PVC ET tube, ventilating a 2-L reservoir bag. A kink was artificially created on the ET tube and ventilated with volume control (VC) and then PC mode. Both modes delivered equal tidal volumes at equal plateau pressures, with higher peak pressures in VC mode. The PC mode with I:E 1:1 delivered higher tidal volume than I:E 1:2 and 2:1 at equal plateau pressures. Whereas previous reports of intraoperative ET tube kinking discussed the detection, diagnosis, cause, and management in scenarios where the tube is readily accessible, we highlight airway pressure characteristics and ventilator management of such a situation when an ET tube was not amenable to remedial solutions.

In Vivo Quantification of the Deformations of the Femoropopliteal Segment: Percutaneous Transluminal Angioplasty vs Nitinol Stent Placement

PURPOSE

To quantify the deformations of the femoropopliteal (FP) segment in patients undergoing endovascular revascularization and to compare the posttreatment deformations caused by primary nitinol stent implantation to those produced by percutaneous transluminal angioplasty (PTA).

METHODS

Thirty-five patients (mean age 69±10 years; 20 men) scheduled for endovascular therapy were recruited for the study. During endovascular interventions, angiographic images were acquired with the legs straight and with a hip/knee flexion of 20°/70°. Image acquisition was performed before PTA for all patients, after PTA in 17 patients receiving this treatment only, and after primary stent implantation in the remaining 18 patients. A semiautomatic approach was used to reconstruct the 3-dimensional patient-specific artery models from 2-dimensional radiographs. Axial shortening and curvature changes in the arteries in vivo were calculated for the calcified, dilated, and stented regions, as well as the regions that were distal and proximal to the diseased and treated segments.

RESULTS

Leg flexion resulted in shortening of the artery in all investigated FP segments. The dilated arteries exhibited greater shortening compared with their stented counterparts (post-PTA 7.6%±4.9%, poststent 3.2%±2.9%; p=0.004). Leg flexion also led to an increase in the curvatures of all the sections of the FP segment. While stented arteries had significantly higher curvature values than PTA within the regions proximal to the treated sections, the choice of the treatment method did not affect the curvature of the other segments. Despite this, 40% of the stented arteries exhibited kinking during leg flexion.

CONCLUSION

The choice of the treatment method affects the postinterventional axial deformations of the FP segment but does not influence the curvature behavior. While PTA results in a more flexible artery, stents restrict the arteries' shortening capabilities. Depending on the anatomical position of the stents, this axial stiffening of the arteries may lead to chronic kinking, which may cause occlusions and, consequently, affect the long-term success of the procedure.

The use of fibrin and gelatin fixation to repair a kinked internal carotid artery in carotid endarterectomy

Background:

The kinking of the internal carotid artery (ICA) after final closure in carotid endarterectomy (CEA) is thought to be uncommon. When it occurs, it is mandatory to reconstruct ICA to preserve normal blood flow. We herein present a case in which a fixation technique was applied to repair an ICA that became kinked during CEA.

Case Description:

A 68-year-old man presented with cerebral infarction due to an artery-to-artery embolism from the right cervical ICA stenosis. CEA was performed 12 days after admission. After final closure, a distal portion of ICA was found to have been kinked following plaque resection in CEA procedure. Fixation with fibrin glue and gelatin was used to reinforce the arterial wall and repair the kink. Postoperative magnetic resonance angiography demonstrated the release of the kink in ICA.

Conclusion:

Fixation with fibrin and gelatin is a salvage armamentarium that can be considered in CEA for the repair of kinked or tortuous ICA.

A simple bracing technique to correct kinking of arterial branches to avoid ischemic sequelae during neurovascular surgery

Background:

During microscopic procedures for neurovascular disease, we sometimes encounter kinking of arterial branches resulting in ischemic sequelae. A simple and useful technique that involves inserting a small, ball-like prosthesis made of oxidized cellulose or shredded Teflon with fibrin glue that corrects the arterial branch kinking and avoids subsequent compromise is reported.

Methods:

Between January and December 2014, three patients developed arterial kinking during microscopic procedures, including two in the caudal loop of the posterior inferior cerebellar artery during microvascular decompression for glossopharyngeal neuralgia and one in a branch of the middle cerebral artery (MCA) during clipping for an unruptured MCA aneurysm. Blood flow insufficiency was confirmed by microvascular Doppler ultrasonography (MDU) and indocyanine green (ICG) videoangiography. The prosthesis, which was made of shredded Teflon in two cases and oxidized cellulose in one case, was inserted into the crotch of the kinked arteries to correct the kinking of the arteries and restore the proper vascular shape and normal blood flow.

Results:

The small, ball-shaped prosthesis corrected the kinked arteries and maintained the proper shape, which was confirmed by ICG videoangiography and MDU during the operation and three-dimensional computerized tomography angiography postoperatively. Postoperatively, the patients did not manifest any ischemic sequelae related to the kinked arteries.

Conclusion:

The insertion of prostheses with fibrin glue into the crotch of a kinked artery for repair is considered a simple and useful method for correcting a kinked artery that avoids ischemic sequelae.

How to discriminate between acute traumatic and chronic degenerative rotator cuff lesions: an analysis of specific criteria on radiography and magnetic resonance imaging

BACKGROUND

Discrimination between acute traumatic and chronic degenerative rotator cuff lesions (RCLs) is an important aid to decision making in therapeutic management. To date, no clinical signs or radiologic findings that enable confident differentiation between these distinct etiologic entities have been identified. The purpose of this investigation was to perform a systematic analysis of known radiographic and magnetic resonance imaging (MRI) features of RCLs and of further, not yet accurately described parameters. The hypothesis was that there are specific radiologic features that allow reliable discrimination between traumatic and nontraumatic RCLs.

METHODS

Fifty consecutive patients with RCLs confirmed by MRI were enrolled in this study. Group A was made up of 25 patients with a history of trauma within the previous 6 weeks and no pre-existing shoulder pain, whereas group B comprised 25 patients with shoulder pain for not more than 12 months and no history of relevant trauma. Radiographs and magnetic resonance images were analyzed in a standardized protocol.

RESULTS

No radiographic features were found to differ significantly between the 2 groups. On MRI, edema in the injured muscle was more common in group A (37.5% vs 4%, P = .04). A characteristic feature in traumatic RCLs was a wavelike appearance (kinking) of the central tendon (64% vs 32%, P = .03). In group B, more muscular atrophy was found (29.2% vs 60%, P = .02). Thinning and retraction did not differ between the groups.

CONCLUSION

MRI, but not radiography, can be used to help discriminate between traumatic and nontraumatic RCLs. Although no absolute distinguishing feature was found, edema, kinking, and muscular atrophy are positive criteria for differentiation.

Bile duct kinking after adult living donor liver transplantation: Case reports and literature review

Regeneration of the partial allograft and the growth of children may cause kinking of the biliary tract after pediatric living donor liver transplantation (LDLT), but bile duct kinking after adult LDLT is rarely reported. We herein presented two patients who suffered from anastomotic strictures caused by severe bile duct kinking after LDLT. The first patient was a 57-year-old woman with hepatitis B virus (HBV)-related liver cirrhosis, who developed biliary stricture 5 months after receiving right-lobe LDLT. Subsequently, endoscopic and percutaneous treatments were attempted, but both failed to solve the problem. The second was a 44-year-old woman also having HBV-related liver cirrhosis. Biliary stricture occurred 14 months after LDLT. Likewise, the guide wire failed to pass through the stricture when endoscopic interventions were conducted. Afterwards, both of the two cases underwent reexploration, showing that compensatory hypertrophy of the allografts resulted in kinking and sharp angulation of the bile ducts, and the anastomotic sites were found to be severely stenotic. Finally, re-anastomosis by Roux-en-Y procedure was successfully performed, and long-term stenosis-free survival was achieved in both of them. Our experience suggests that bile duct kinking after LDLT may play a role in the high incidence of anastomotic strictures in adult LDLT recipients, which may also result in the treatment failure of the non-surgical techniques for anastomotic strictures. Re-anastomosis in the form of Roux-en-Y hepaticojejunostomy is an effective surgical option for the treatment of such a condition.

Significant Association between Carotid Artery Kinking and Leukoaraiosis in Middle-Aged and Elderly Chinese Patients

BACKGROUND

Leukoaraiosis (LA) and carotid artery morphologic variations are 2 common imaging manifestations. The purpose of this study was to determine whether carotid artery morphologic variations are correlated with LA.

METHODS

A total of 702 patients, aged 50 years or older, admitted to our hospital from November 1, 2013, to January 30, 2014, were prospectively enrolled in this study. All participants underwent magnetic resonance imaging to assess the presence and severity of LA. Carotid artery morphologic variations were classified into tortuosity, kinking, and coiling by computed tomography angiography. Logistic regression analyses were performed to examine the relationship between carotid artery morphologic variations, its components, and LA.

RESULTS

The frequency of hemisphere with LA and carotid artery with carotid artery morphologic variations was 49.9% and 70.3% in the cohort, respectively. Carotid kinking was associated with an increased risk of ipsilateral LA after multivariable adjustment (odds ratio [OR], 2.29; 95% confidence interval [CI], 1.57-3.36 for left side; OR, 2.51; 95% CI: 1.68-3.74 for right side), whereas carotid tortuosity and coiling were not related to LA. Moreover, the prevalence of carotid kinking gradually increased with advancing grades of ipsilateral LA.

CONCLUSIONS

The present study demonstrated that carotid artery kinking may be associated with an increased risk of LA in middle-aged and elderly Chinese patients. Further prospective studies are needed to confirm these findings.

Controlled synthesis of kinked ultrathin ZnS nanorods/nanowires triggered by chloride ions: a case study

Colloidal synthesis of kinked ultrathin ZnS nanorods/nanowires with mixed phases using tiny Ag2S nanocrystals as catalysts is reported. It is found that chloride ions can induce the controlled morphology transition from straight to kinking. The synthetic parameters modulating the growth of kinked ZnS nanorods/nanowires are systematically investigated. Chloride ions introduced in the reaction can generate more proportion of wurtzite phase by slowing the nucleation and growth rates during the growth of one-dimensional (1D) ZnS nanorods/nanowires. The formation of kinked morphology is responsible for the increased domains of mixed stacking and twinning in single 1D nanostructures. The present recipe on controlled synthesis of 1D kinked nanorods/nanowires provides a model of crystal growth control, and these unique 1D nanostructures may also offer new opportunities to fabricate nanodevices with special functions.