Segmentation of Prefrontal Lobe Based on Improved Clustering Algorithm in Patients with Diabetes.

Diabetics are prone to postoperative cognitive dysfunction (POCD). The occurrence may be related to the damage of the prefrontal lobe. In this study, the prefrontal lobe was segmented based on an improved clustering algorithm in patients with diabetes, in order to evaluate the relationship between prefrontal lobe volume and COPD. In this study, a total of 48 diabetics who underwent selective noncardiac surgery were selected. Preoperative magnetic resonance imaging (MRI) images of the patients were segmented based on the improved clustering algorithm, and their prefrontal volume was measured. The correlation between the volume of the prefrontal lobe and Z-score or blood glucose was analyzed. Qualitative analysis shows that the gray matter, white matter, and cerebrospinal fluid based on the improved clustering algorithm were easy to distinguish. Quantitative evaluation results show that the proposed segmentation algorithm can obtain the optimal Jaccard coefficient and the least average segmentation time. There was a negative correlation between the volume of the prefrontal lobe and the Z-score. The cut-off value of prefrontal lobe volume for predicting POCD was <179.8, with the high specificity. There was a negative correlation between blood glucose and volume of the prefrontal lobe. From the results, we concluded that the segmentation of the prefrontal lobe based on an improved clustering algorithm before operation may predict the occurrence of POCD in diabetics.

Frequency, Determinants, and Outcomes of Emboli to Distal and New Territories Related to Mechanical Thrombectomy for Acute Ischemic Stroke.

Background and Purpose: Clot fragmentation and distal embolization during endovascular thrombectomy for acute ischemic stroke may produce emboli downstream of the target occlusion or in previously uninvolved territories. Susceptibility-weighted magnetic resonance imaging can identify both emboli to distal territories (EDT) and new territories (ENT) as new susceptibility vessel signs (SVS). Diffusion-weighted imaging (DWI) can identify infarcts in new territories (INT). Methods: We studied consecutive acute ischemic stroke patients undergoing magnetic resonance imaging before and after thrombectomy. Frequency, predictors, and outcomes of EDT and ENT detected on gradient-recalled echo imaging (EDT-SVS and ENT-SVS) and INT detected on DWI (INT-DWI) were analyzed. Results: Among 50 thrombectomy-treated acute ischemic stroke patients meeting study criteria, mean age was 70 (±16) years, 44% were women, and presenting National Institutes of Health Stroke Scale score 15 (interquartile range, 8­19). Overall, 21 of 50 (42%) patients showed periprocedural embolic events, including 10 of 50 (20%) with new EDT-SVS, 10 of 50 (20%) with INT-DWI, and 1 of 50 (2%) with both. No patient showed ENT-SVS. On multivariate analysis, model-selected predictors of EDT-SVS were lower initial diastolic blood pressure (odds ratio, 1.09 [95% CI, 1.02­1.16]), alteplase pretreatment (odds ratio, 5.54 [95% CI, 0.94­32.49]), and atrial fibrillation (odds ratio, 7.38 [95% CI, 1.02­53.32]). Classification tree analysis identified pretreatment target occlusion SVS as an additional predictor. On univariate analysis, INT-DWI was less common with internal carotid artery (5%), intermediate with middle cerebral artery (25%), and highest with vertebrobasilar (57%) target occlusions (P=0.02). EDT-SVS was not associated with imaging/functional outcomes, but INT-DWI was associated with reduced radiological hemorrhagic transformation (0% versus 54%; P<0.01). Conclusions: Among acute ischemic stroke patients treated with thrombectomy, imaging evidence of distal emboli, including EDT-SVS beyond the target occlusion and INT-DWI in novel territories, occur in about 2 in every 5 cases. Predictors of EDT-SVS are pretreatment intravenous fibrinolysis, potentially disrupting thrombus structural integrity; atrial fibrillation, possibly reflecting larger target thrombus burden; lower diastolic blood pressure, suggestive of impaired embolic washout; and pretreatment target occlusion SVS sign, indicating erythrocyte-rich, friable target thrombus.

Transient changes in white matter microstructure during general anesthesia.

Cognitive dysfunction after surgery under general anesthesia is a well-recognized clinical phenomenon in the elderly. Physiological effects of various anesthetic agents have been studied at length. Very little is known about potential effects of anesthesia on brain structure. In this study we used Diffusion Tensor Imaging to compare the white matter microstructure of healthy control subjects under sevoflurane anesthesia with their awake state. Fractional Anisotropy, a white mater integrity index, transiently decreases throughout the brain during sevoflurane anesthesia and then returns back to baseline. Other DTI metrics such as mean diffusivity, axial diffusivity and radial diffusivity were increased under sevoflurane anesthesia. Although DTI metrics are age dependent, the transient changes due to sevoflurane were independent of age and sex. Volumetric analysis shows various white matter volumes decreased whereas some gray matter volumes increased during sevoflurane anesthesia. These results suggest that sevoflurane anesthesia has a significant, but transient, effect on white matter microstructure. In spite of the transient effects of sevoflurane anesthesia there were no measurable effects on brain white matter as determined by the DTI metrics at 2 days and 7 days following anesthesia. The role of white matter in the loss of consciousness under anesthesia will need to be studied and MRI studies with subjects under anesthesia will need to take these results into account.

Postoperative cognitive dysfunction: an acute approach for the development of novel treatments for neuroinflammation.

Inflammation within the central nervous system (CNS; neuroinflammation) is a major contributor to lasting symptoms of traumatic brain injury and stroke, and likely has a casual role Alzheimer's disease (AD) and other neurodegenerative conditions. Therapeutic modulation of the immune processes that initiate and maintain neuroinflammation is of growing scientific interest but neuroinflammatory drug development is hampered by limited reliability and availability of neuroimaging or other biomarkers in humans. Better means of establishing drug efficacy on human neuroinflammation would have great value in accelerating the development of neuroinflammatory compounds for many clinical indications. Here, we discuss the use of postoperative cognitive decline (POCD), which is hypothesised to have a neuroinflammatory basis, as an acute indication to demonstrate the efficacy of novel neuroinflammatory drugs.

Relationship between Deep White Matter Hyperintensities on Magnetic Resonance Imaging and Postoperative Cognitive Function Following Clipping of Unruptured Intracranial Aneurysm.

To evaluate the effects on cognitive function of deep white matter hyperintensities (DWMHs) on magnetic resonance imaging (MRI) in patients treated surgically for unruptured intracranial aneurysms (UIAs). The subjects were 106 patients in whom a Wechsler adult intelligence scale-revised (WAIS-R) examination was performed 1 week before and 1 month after clipping surgery for asymptomatic UIAs. DWMH severity was evaluated on preoperative MR images by Fazekas scale, as follows: none (absence), mild (punctate foci), moderate (beginning confluence of foci), or severe (large confluent areas). A decrease of 7 or more points in intelligence quotient (IQ) postoperatively was considered deterioration. Fazekas score was none in 41 (none group), mild in 42 (mild group), moderate in 21, and severe in 2 patients (moderate/severe group). Patient characteristics, surgical factors, IQ change, and abnormal findings on postoperative MRI were compared among the groups. Although there was no statistically significant deterioration in IQ postoperatively in any group, the percentage of deteriorated patients was significantly higher in the moderate/severe group (34.8%) than in the other groups (4.9% in the none group, 7.1% in the mild group; p <0.01, p <0.05, respectively). Brain injury was observed more frequently on postoperative MR images in the moderate/severe group (17.4%) compared with the none group (2.4%; p = 0.052). The presence of moderate/severe DWMHs was an independent prognostic factor for postoperative cognitive dysfunction. In conclusion, the presence of moderate/severe DWMHs was a prognostic factor for postoperative cognitive dysfunction after surgery for UIAs.

Timing of thoracic endovascular aortic repair for uncomplicated acute type B aortic dissection and the association with complications.

OBJECTIVE: Previous publications have clearly established a correlation between timing of thoracic endovascular aortic repair (TEVAR) and complications after treatment of complicated acute type B aortic dissection (ATBAD). However, the temporal association of TEVAR with morbidity after uncomplicated presentations is poorly understood and has not previously been examined using real-world national data. Therefore, the objective of this analysis was to determine whether TEVAR timing of uncomplicated ATBAD (UATBAD) is associated with postoperative complications. METHODS: The Vascular Quality Initiative TEVAR and complex endovascular aneurysm repair registry was analyzed from 2010 to 2019. Procedures performed for non-dissection-related disease as well as for ATBAD with malperfusion or rupture were excluded. Because of inherent differences between timing cohorts, propensity score matching was performed to ensure like comparisons. Univariate and multivariable analysis after matching was used to determine differences between timing groups (symptom onset to TEVAR: acute, 1-14 days; subacute, 15-90 days) for postoperative mortality, in-hospital complications, and reintervention. RESULTS: A total of 688 cases meeting inclusion criteria were identified. After matching 187 patients in each of the 1- to 14-day and 15- to 90-day treatment groups, there were no statistically significant differences between groups. On univariate analysis, the 1- to 14-day treatment group had a higher proportion of cases requiring reintervention within 30 days (15.3%) compared with UATBAD patients undergoing TEVAR within 15 to 90 days (5.2%; P = .02). There was also a difference (P = .007) at 1 year, with 33.8% of the 1- to 14-day UATBAD patients undergoing reintervention compared with 14.5% for the 15- to 90-day group. There were no statistically significant differences on multivariable analysis for long-term survival, complications, or long-term reintervention. There was a trend toward significance (P = .08) with the 1- to 14-day group having 2.3 times the odds of requiring an in-hospital reintervention compared with the 15- to 90-day group. CONCLUSIONS: Timing of TEVAR for UATBAD does not appear to predict mortality or postoperative complications. However, there is a strong association between repair within 1 to 14 days and higher risk of reintervention. This may in part be related to the 1- to 14-day group's representing an inherently higher anatomic or physiologic risk population that cannot be entirely accounted for with propensity analysis. The role of optimal timing to intervention should be incorporated into future study design of TEVAR trials for UATBAD.

Influence of Luminal Communication on Aortic Enlargement after Hemiarch Replacement for Acute Type A Aortic Dissection.

BACKGROUND: Aortic enlargement after hemiarch replacement (HAR) for acute type A aortic dissection (AAAD) is a serious problem. We reviewed our experience and analyzed the risk factors for aortic enlargement. METHODS: During April 2005 to December 2017, 364 patients underwent HAR for AAAD. Seventy-three patients fulfilled the inclusion criteria. We analyzed the change in aortic diameter, aortic growth rate, and major adverse aortic events (MAAEs) and their association with luminal communication of the aortic arch. RESULTS: Anastomotic communication, supra-aortic communication (SAC), and distal aortic communication were found in 34 (46.6%), 28 (38.4%), and 20 (27.4%) patients, respectively. The aortic growth rate was high because of the presence of SAC, distal aortic communication, and the number of coexisting aortic communication. Univariate analysis showed that the presence of SAC and an initial aortic diameter > 35 mm at 20 mm distal to the left subclavian artery and at the pulmonary artery bifurcation (PAB) were risk factors for MAAEs. Multivariate analysis showed that SAC and an initial aortic diameter > 35 mm at the PAB were independent risk factors for MAAEs. CONCLUSION: SAC, distal aortic communication, and the number of coexisting aortic communication are significant risk factors for aortic enlargement after HAR for AAAD. SAC and an initial aortic diameter > 35 mm at the PAB are independent risk factors for MAAEs after this procedure.

Prognosis of Transcatheter Closure Compared with Surgical Repair of Paravalvular Leak after Prosthetic Valve Replacement: A Retrospective Comparison.

OBJECTIVE: Paravalvular leak (PVL) after valve replacement remains clinically challenging. Percutaneous closure is an effective therapy for patients with PVLs because reoperation is associated with high rates of morbidity and mortality. The purpose of this study was to retrospectively compare the clinical outcome of transcatheter closure and surgical repair in patients with a PVL. METHODS: From January 2000 to May 2016, 131 patients with PVL were treated at three major medical centers in China. Perioperative characteristics and outcomes of the procedure were reviewed. RESULTS: Sixty-eight (51.9%) patients with PVLs were treated with percutaneous transcatheter closure (group I). The procedure was successful in 67 (98%) with no hospital deaths. Sixty-three (48.1%) patients with PVLs had a reoperation (group II). Five of the surgical patients had a third open-heart operation for residual regurgitation, and one underwent successful percutaneous closure. Six patients died in the hospital postoperatively. All patients in group II but only 11 in group I needed perioperative blood transfusions. The procedural time and hospital stay after the procedure were significantly shorter in group I than in group II. At the 1-year follow-up, cardiac function improved by ≥ 1 New York Heart Association functional class in 55 (82%) patients in group I and in 39 (68%) patients in group II. CONCLUSIONS: Transcatheter closure was shown to be a safe, effective therapeutic option in patients with PVL. It was associated with a lower hospital mortality rate, shorter procedural time, and fewer blood transfusions than surgical treatment in selected patients.

Imaging for Predicting, Detecting, and Managing Complications After Transcatheter Aortic Valve Replacement.

The management of patients with valvular heart disease is increasingly reliant on multimodal cardiac imaging. In patients with severe aortic stenosis considered for transcatheter aortic valve replacement, careful pre-procedural planning with multimodal imaging is necessary to avoid and prevent complications during the procedure. During or immediately after the procedure, rapid echocardiographic assessment is important to assess the new valve's function and manage major complications. Echocardiography, cardiac computed tomography, and cardiac magnetic resonance imaging all share important roles in the post-procedural evaluation of abnormal transcatheter valve function. This review discusses the use of multimodal imaging for predicting, detecting, and managing complications after TAVR.

Ogilvie syndrome in a 8 year old girl after laparoscopic appendectomy.

BACKGROUND: Ogilvie's syndrome is described in the adult population, but rarely seen in children. CASE PRESENTATION: We present a case of a girl who suffered acute colonic pseudo-obstruction after laparoscopic appendectomy. CONCLUSIONS: Ogilvie's syndrome, although rare in the pediatric population, should be considered as possible diagnosis after a surgical procedure in presence of persisting subocclusive symptoms and radiological signs of massive colonic dilatation without mechanical obstruction.

Domain-specific cognitive dysfunction after cardiac surgery. A secondary analysis of a randomized trial.

BACKGROUND: Brain injury and cognitive dysfunction are serious complications after cardiac surgery. In the perfusion pressure cerebral infarcts (PPCI) trial, we allocated cardiac surgery patients to a mean arterial pressure of either 70-80 mm Hg (high-target) or 40-50 mm Hg (low-target) during cardiopulmonary bypass. In this secondary analysis, we aimed to assess potential differences in domain-specific patterns of cognitive deterioration between allocation groups and to investigate any associations of postoperative cognitive dysfunction (POCD) with diffusion-weighted magnetic resonance imaging (DWI)-detected brain lesions. METHODS: Of the 197 patients randomized in the PPCI trial, 89 in the low-target group and 80 in the high-target group had complete DWI datasets, and 92 and 80 patients had complete data for an evaluation of cognitive function at discharge respectively. Cognitive function was assessed prior to surgery, at discharge and at 3 months. DWI was obtained at baseline and on postoperative days 3 to 6. RESULTS: We found no statistically significant differences between the two groups when comparing the proportion of patients with a domain-specific deterioration over the pre-defined critical level in seven individual test variables at discharge. Significant deterioration was most common in tests thought to assess cognitive flexibility and interference susceptibility and least common in the memory test. POCD at discharge was more frequent in patients with DWI-positive brain lesions (OR adjusted for age and group allocation: 2.24 [95% CI 1.48-3.00], P = 0.036). CONCLUSIONS: Domain-specific patterns of POCD were comparable between groups. A significant association was seen between DWI-positive brain lesions and POCD.

Assessment of delayed graft function using susceptibility-weighted imaging in the early period after kidney transplantation: a feasibility study.

PURPOSE: This study aimed to explore the feasibility of susceptibility-weighted imaging (SWI) for evaluating delayed graft function (DGF) during the early posttransplantation period. METHODS: Sixty-nine recipients who accepted allograft renal transplantation underwent SWI during the second posttransplantation week. Renal allograft function was estimated via the glomerular filtration rate. Recipients with and without DGF were identified. For each transplanted kidney, the presence of abnormal signal intensity lesions (ASILs), excluding benign lesions, on SWI was assessed. Renal allograft function was compared between the recipients with and without ASILs. The correlation between ASILs and renal allograft function was tested by Spearman's rank correlation analysis. RESULTS: Thirty-four recipients were diagnosed with DGF, while 35 recipients showed no DGF. In the DGF group, 16 recipients had low-intensity ASILs, primarily at the corticomedullary junction of transplanted kidneys on SWI, and no ASILs were found in 18 recipients. In the non-DGF group, none of the recipients showed ASILs on SWI. In the DGF group, the renal allograft function among the 16 recipients with low-intensity ASILs was significantly lower than that among the other 18 recipients (8.5 ± 4.2 vs. 19.7 ± 9.7 mL/min, P < 0.001). The presence of low-intensity ASILs on SWI showed a moderate negative correlation with renal allograft function in recipients with DGF (r = - 0.553, P = 0.001). CONCLUSION: SWI can be used to evaluate DGF in the early post-kidney transplantation period.