Tailored Vessel-Catheter Diameter Ratio in a Direct Aspiration First-Pass Technique: Is It a Matter of Caliber?

BACKGROUND AND PURPOSE: The aspiration technique has gained a prominent role in mechanical thrombectomy. The thrombectomy goal is successful revascularization (modified TICI ≥ 2b) and first-pass effect. The purpose of this study was to evaluate the impact of the vessel-catheter ratio on the modified TICI ≥ 2b and first-pass effect. MATERIALS AND METHODS: This was a retrospective, single-center, cohort study. From January 2018 to April 2020, 111/206 (53.9%) were eligible after applying the exclusion criteria. Culprit vessel diameters were measured by 2 neuroradiologists, and the intraclass correlation coefficient was calculated. The receiver operating characteristic curve was used for assessing the vessel-catheter ratio cutoff for modified TICI ≥ 2b and the first-pass effect. Time to groin puncture and fibrinolysis were weighted using logistic regression. All possible intervals (interval size, 0.1; sliding interval, 0.01) of the vessel-catheter ratio were plotted, and the best and worst intervals were compared using the χ2 test. RESULTS: Modified TICI ≥ 2b outcome was achieved in 75/111 (67.5%), and first-pass effect was achieved in 53/75 (70.6%). The MCA diameter was 2.1 mm with an intraclass correlation coefficient of 0.92. The optimal vessel-catheter ratio cutoffs for modified TICI ≥ 2b were ≤1.51 (accuracy = 0.67; 95% CI, 0.58-0.76; P = 0.001), and for first-pass effect, they were significant (≤1.33; P = .31). The modified TICI ≥ 2b odds ratio and relative risk were 9.2 (95% CI, 2.4-36.2; P = 0.002) and 3.2 (95% CI, 1.2-8.7; P = .024). The odds ratio remained significant after logistic regression (7.4; 95% CI, 1.7-32.5; P = .008). First-pass effect odds ratio and relative risk were not significant (2.1 and 1.5; P > .05, respectively). The modified TICI ≥ 2b best and worst vessel-catheter ratio intervals were not significantly different (55.6% versus 85.7%, P = .12). The first-pass effect best vessel-catheter ratio interval was significantly higher compared with the worst one (78.6% versus 40.0%, P = .03). CONCLUSIONS: The aspiration catheter should be selected according to culprit vessel diameter. The optimal vessel-catheter ratio cutoffs were ≤1.51 for modified TICI ≥ 2b with an odds ratio of 9.2 and a relative risk of 3.2.

Functional recovery of callosal axons following demyelination: a critical window.

Axonal dysfunction as a result of persistent demyelination has been increasingly appreciated as a cause of functional deficit in demyelinating diseases such as multiple sclerosis. Therefore, it is crucial to understand the ultimate causes of ongoing axonal dysfunction and find effective measures to prevent axon loss. Our findings related to functional deficit and functional recovery of axons from a demyelinating insult are important preliminary steps towards understanding this issue. Cuprizone diet for 3-6 wks triggered extensive corpus callosum (CC) demyelination, reduced axon conduction, and resulted in loss of axon structural integrity including nodes of Ranvier. Replacing cuprizone diet with normal diet led to regeneration of myelin, but did not fully reverse the conduction and structural deficits. A shorter 1.5 wk cuprizone diet also caused demyelination of the CC, with minimal loss of axon structure and nodal organization. Switching to normal diet led to remyelination and restored callosal axon conduction to normal levels. Our findings suggest the existence of a critical window of time for remyelination, beyond which demyelinated axons become damaged beyond the point of repair and permanent functional loss follows. Moreover, initiating remyelination early within the critical period, before prolonged demyelination-induced axon damage ensues, will improve functional axon recovery and inhibit disease progression.

Usefulness of transesophageal echocardiography during open heart surgery of mitral stenosis.

BACKGROUND: The aim of this study was to verify if the use of intraoperative transesophageal echocardiography (TEE), by detecting mitral insufficiency or residual stenosis during surgery, may improve medium term results in patients with severe mitral stenosis who undergo open heart valvuloplasty. METHODS: This prospective study included twenty-two patients (20 women and 2 men) with a mean age of 49+/-13 years with severe mitral stenosis. Mean follow-up was 32 months (range 12-55 months). All the patients underwent transthoracic echocardiography (TrE) before surgery and intraoperative TEE. Before surgery the mean transmitral gradient was 11+/-6.8 mmHg, the mean pressure half time (PHT) area was 0.89+/-0.19 cm2, the mean echo score was 8.9+/-2.2. Intraoperative TEE before the repair showed a mean echo score of 7.9+/-1.8. RESULTS: Two patients with unsatisfactory repair at TEE underwent immediate valve replacement. In the remaining patients, mean transmitral gradient and PHT valve area before discharge was 5.2+/-3 mmHg and 2.5 cm2. No patients had more than trivial mitral regurgitation. During the follow-up two patients had to be reoperated. Patients with poor immediate (2 patients) or medium term results (2 patients), had a mean echocardiographic score of 12.24, while patients with a satisfactory medium term outcome had a mean score of 7.27 (p<0.001). CONCLUSIONS: Intraoperative TEE may guide the surgeon in the assessment of valvuloplasty. However the absence of mitral regurgitation after repair and at discharge cannot predict the medium term results, which are related to the degree of the disease of the mitral valve.

[Conservative surgical treatment of rheumatic mitral stenosis]. / Terapia chirurgica conservativa della stenosi mitralica reumatica.

We prospectively evaluated 50 patients with mitral stenosis (43 women and 7 men; mean age 45 years) to assess the results of surgical reconstruction of the mitral valve. All patients underwent a complete echocardiographic examination before and after operation. Surgical reconstruction was extensive, and included commissurotomy, thinning of the valvular leaflets, calcification removal, splitting of subvalvular apparatus, and posterior annuloplasty. Surgical reconstruction resulted in increasing mitral functional area from 0.89 +/- 0.23 to 2.07 +/- 0.42 cm2. NYHA functional class decreased from 2.76 +/- 0.55 to 1.52 +/- 0.71. Before discharging, 10% of patients had moderate mitral insufficiency. All patients were followed at 6-month intervals in our clinic. Mean follow-up was 37 +/- 18 months. During follow-up 5 patients (10%) developed severe mitral incompetence, which required mitral valve replacement. Chi-square and Student t-test were used to analyze the correlation between variables and outcome. The occurrence of severe mitral incompetence was correlated with: the degree of enlarged left atrium; chronic atrial fibrillation; postoperative more than mild mitral regurgitation. No correlation was found with anatomical parameters detected by echocardiography, or intraoperative anatomy. In conclusion, surgical reconstruction of mitral stenosis provides satisfactory short-term results. We believe that the low mortality rate and the low incidence of complications justify an effort to save the native mitral valve before considering prosthetic replacement. More attention to the development of residual mitral incompetence with intraoperative control may improve long-term results.