Laparoscopic Co-surgeon Ventriculoperitoneal Shunt Placement Versus Single Surgeon Mini Laparotomy

Introduction: Ventriculoperitoneal (VP) shunt placement is one of the most common treatments for pediatric hydrocephalus. However, device failures often occur, requiring operative revision of either the intraventricular or intraperitoneal shunt catheters. Historically, shunt placement was performed via laparotomy, but there has been a trend towards laparoscopic-assisted placement of the intraperitoneal portion of the shunt. We examined the outcomes of laparoscopic-assisted versus open VP shunt placement utilizing a local institutional retrospective review.

Methods: Single institution 2012-2017 retrospective review of all cases was performed. Patients were divided into two groups - laparoscopic and open. Thirty-day outcomes, patient age, surgery performed, surgical control time (SCT), length of stay (LOS), and readmission were analyzed. 

Results: Cohort analysis inclusion criteria included 188 patients. The cohort analysis showed both decreased laparoscopic-assisted SCT (56.4 vs 32.1 min, p<0.0001) and postop complications (16.7% vs 7.1%, p<0.07). There was no significant difference in surgical site infection or readmission rates. 

Conclusion: Local analysis show advantages for laparoscopic-assisted VP shunt placement over open single surgeon techniques with decreased SCT, LOS, and unplanned interventions.

POS0429 ACTIVATED RHEUMATOID ARTHRITIS SYNOVIAL FIBROBLASTS ALTER OSTEOCLAST DIFFERENTIATION AND ACTIVITY

Background

In rheumatoid arthritis (RA), osteoclasts are one of the most important mediators of bone erosion. In addition, RA synovial fibroblasts (RASF) have a major influence on joint erosion in RA. They affect osteoclast differentiation e.g. by increased RANKL production or secretion of other pro-osteoclastogenic factors such as IL-6. In addition to the pro-osteoclastogenic effect of soluble factors such as RANKL and IL-1, visfatin inhibits osteoclast differentiation. Furthermore, visfatin increases the secretion of pro-inflammatory factors by RASF, such as IL-6 or matrix degrading enzymes.

Objectives

In this study, the effect of RASF with/without activation by visfatin and IL-1 on osteoclastogenesis was evaluated.

Methods

Blood from healthy donors and RA patients was used for PBMC isolation. RANKL, TGF-β and hM-CSF were added to induce osteoclast differentiation. RASF-conditioned media (CM) were prepared from confluent RASF cultured for 48h. Differentiating PBMCs in monoculture were compared to PBMC cultured with CM from RASF (CM: 10%, 20%, 30%) as well as in direct co-culture with RASF with/without stimulation with IL-1 (0.05ng/ml), visfatin (25ng/ml). After two weeks in culture, cells were stained using TRAP staining. 3-5 images per well were used for quantification dependent on the variability of the wells. IL-6 was measured by ELISA in supernatants collected at day 14.

Results

IL-6 production increased by IL-1 (e.g. co-culture: 2,8-fold) and visfatin (CM-visfatin: 10%=4,3-fold, 20%=5,4-fold, 30%=4,2-fold; co-culture: 9,5-fold) compared to unstimulated control in all settings. In addition, IL-6 was increased with the addition of CM compared to unstimulated controls (healthy donors CM 30%: unstimulated p=0.0342, IL-1 p=0.0133, visfatin p=0,0133; RA: unstimulated p=0.0133, IL-1 p=0.0342, visfatin p=0.0133, n=3 each). Of note, baseline IL-6 concentrations were higher in PBMC from RA patients compared to healthy donors. Co-culture showed an additional increase in IL-6 levels in all settings (e.g. monoculture: IL-1 4.71±5.75pg/ml, visfatin 141.09±182.79pg/ml; co-culture: IL-1 7241±10398pg/ml, visfatin 24535±16994pg/ml;). During osteoclast differentiation, addition of CM showed similar osteoclastogenesis with similar proportion of osteoclasts with 2 and 3-5 vs. higher numbers of nuclei per cell compared to control. In coculture with RASF osteoclasts showed a stronger TRAP signal compared to monoculture especially for unstimulated and IL-1 stimulated co-cultures.

Conclusion

Both, in monoculture with CM and in coculture, IL-6 levels were increased compared to control, whereas in RA patients the IL-6 levels were higher compared to healthy donors. The CM containing secreted factors of RASF did not have a prominent influence on osteoclastogenesis. However, the presence of RASF increased the TRAP signal showing an increased activity of differentiated osteoclasts especially in unstimulated and IL-1 stimulated co-cultures but not with addition of visfatin.

References

None.

Disclosure of Interests

None declared.

Diagnostic Accuracy of High-Resolution 3D T2-SPACE in Detecting Cerebral Venous Sinus Thrombosis

BACKGROUND AND PURPOSE

Assessment of cerebral venous sinus thrombosis on MR imaging can be challenging. The aim of this study was to evaluate the diagnostic accuracy of high-resolution 3D T2 sampling perfection with application-optimized contrasts by using different flip angle evolution (SPACE) in patients with cerebral venous sinus thrombosis and to compare its performance with contrast-enhanced 3D T1-MPRAGE.

MATERIALS AND METHODS

We performed a blinded retrospective analysis of T2-SPACE and contrast-enhanced MPRAGE sequences from patients with cerebral venous sinus thrombosis and a control group. The results were compared with a reference standard, which was based on all available sequences and clinical history. Subanalyses were performed according to the venous segment involved and the clinical stage of the thrombus.

RESULTS

Sixty-three MR imaging examinations from 35 patients with cerebral venous sinus thrombosis and 51 examinations from 40 control subjects were included. The accuracy, sensitivity, and specificity calculated from the initial MR imaging examination for each patient were 100% each for T2-SPACE and 95%, 91%, and 98%, respectively, for contrast-enhanced MPRAGE. The interrater reliability was high for both sequences. In the subanalysis, the accuracy for each venous segment involved and if subdivided according to the clinical stage of thrombus was ≥95% and ≥85% for T2-SPACE and contrast-enhanced MPRAGE, respectively.

CONCLUSIONS

Both T2-SPACE and contrast-enhanced MPRAGE offer high accuracy for the detection and exclusion of cerebral venous sinus thrombosis; however, T2-SPACE showed a better overall performance and thus could be a useful tool if included in a multiparametric MR imaging protocol for the diagnosis of cerebral venous sinus thrombosis, especially in scenarios where gadolinium administration is contraindicated.

Joint effects of general population polygenic risk scores (PRS) and radiation treatment on subsequent neoplasm risk among childhood cancer survivors: A report from the Childhood Cancer Survivor Study (CCSS)

10008

Background: We examined whether PRS from general population studies are associated with risk of subsequent neoplasms (SNs) in childhood cancer survivors and evaluated joint associations between PRS and radiation treatment (RT), an established SN risk factor. Methods: Common genetic variants associated with risk of basal cell carcinoma (BCC), breast cancer, thyroid cancer, squamous cell carcinoma (SCC) or melanoma in general population studies were used to calculate cancer specific PRS among 5,911 5 year cancer survivors diagnosed < 21 years of age and between 1970-1986 in the CCSS. We examined associations between each PRS and SN risk using conditional logistic regression in nested case control studies, with incidence density sampling and matching on childhood cancer type, age at diagnosis, sex, RT dose to the SN site, and chemotherapy exposure. Further analyses matching only on non-treatment factors assessed joint associations considering potential combinations of PRS and RT exposure. We calculated the relative excess risk due to interaction (RERI) to determine whether joint associations were consistent with additivity of the individual risk factors (RERI > 0 indicates a more-than-additive joint association). Results: Among survivors (median age at follow-up 40 years, range 3-67; 62% exposed to RT), cancer specific PRS were associated with risk of subsequent BCC (N = 626; quartile 4 versus 1, OR [95% CI] = 1.9 [1.5-2.4]), breast cancer (N = 277; 4.5 [2.8-7.1]), thyroid cancer (N = 149; 1.9 [1.2-3.1]), and melanoma (N = 76; 2.7 [1.3-5.6]). Both PRS and RT were independently associated with SN risk, but joint analyses using a common reference group (PRS < median, RT < 1 Gy) found that both risk factors together resulted in more-than-additive increases in risk of BCC (RERI [95% CI] = 6.9 [2.0-11.8], breast cancer (6.6 [2.2-10.1], and thyroid cancer (4.8 [0.5-9.2]). Specifically, BCC risk was increased 28.8-fold for both PRS ≥ median and RT ≥ 1 Gy together, but only 3.3-fold for PRS ≥ median alone and 19.7-fold for RT ≥ 1 Gy alone. Similarly, breast cancer risk was increased 14.1-fold for both risk factors together, 2.5-fold for PRS ≥ median alone, and 6.5-fold for RT ≥ 1 Gy alone, and thyroid cancer risk was increased 12.3-fold for both risk factors together, 2.4-fold for PRS ≥ median alone, and 6.0-fold for RT ≥ 1 Gy alone. In joint analyses using more detailed RT categories, we found more-than-additive joint associations at both low and high RT doses. Conclusions: General population PRS were associated with SN risks after childhood cancer. More-than-additive increased risks with the combination of PRS and RT suggest that established markers of genetic susceptibility remain important in the context of treatment-related risks and may be useful in further refining risk assessment and follow-up guidelines for survivors.

Real-world experience on implantation and atrial signal detection of a SC ICD with atrial sensing capability: The MATRIX study

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): BIOTRONIK, Berlin, Germany

Introduction

A single-lead implantable cardioverter-defibrillator (ICD) with atrial sensing dipole (the DX ICD system) can potentially give additive information concerning atrial diagnostics in patients requiring only a single-chamber ICD. We therefore report the real-world experience from large DX registry on implantation, atrial signal quality and detection and the long-term stability of the atrial signal.

Methods

The prospective, single-arm MATRIX (Management and Detection of Atrial Tachyarrhythmias in Patients Implanted With BIOTRONIK DX Systems, NCT01774357) registry study effectively enrolled 2041 patients at 119 sites in 24 countries. All patients had a DX system implanted for a single-chamber ICD indication for primary or secondary prevention of sudden cardiac death. Patients were followed for 24 months including remote monitoring. Implantation and follow-up data are reported for the whole patient set. For the analyses on atrial sensing amplitude values, remotely transmitted device measurements of patients without history of long-standing persistent or permanent AF at baseline were used.

Results

The mean follow-up period was 677±173 days. Implantation took place at 15±22 days before enrollment. Baseline and implantation data are shown in the table. Implantation procedure and lead insertion were rated as "easy" or "very easy" in 91.0% and 96.3% of assessments, respectively. At implantation, the investigators rated the quality of the atrial sensing amplitude as "sufficient" in 97% of the assessed cases. At enrollment (12-month/24-month follow-up), the atrial signal quality and detection were rated as "good" or "excellent" in 92.3% (89.8%/89.9%) and 92.4% (90.1%/91.3%) of assessments, respectively. For 1841 patients (90.2%), remotely transmitted device information was received. The median (mean ± SD, IQR) transmission rate was 92.5% (85.4±18.2%, 81.4-97.3%). 1746 patients (85.5%) matched the inclusion criteria for the quantitative analyses on atrial sensing. 95.6% of available RA sensing amplitude values were ≥1 mV. Based on each patient’s overall median value, the median (mean ± SD, IQR) RA sensing amplitude was 4.6 mV (4.4±2.0 mV, 2.8-6.2 mV). The time course of patient median values stratified by month is shown in the figure.

Conclusion

The study followed 2041 patients implanted with the DX ICD system for two years. In the vast majority of cases, investigators rated implantation as (very) easy and the atrial signal over 24 months as good/excellent. According to daily, automatic Home Monitoring data, the overall mean P-wave amplitude remained stable throughout the whole follow-up. The MATRIX study demonstrated functionality and clinical utility of the DX concept in an unselected, real-life setting.

Capability of guideline-conform remote atrial high rate episode monitoring with a single-chamber implantable defibrillator with atrial sensing

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): BIOTRONIK, Berlin, Germany

Introduction

Device-detected atrial high-rate episodes (AHRE) and their burden progression are associated with an increased risk for thromboembolic events in correlation with CHA2DS2-VASc score and AHRE burden. To allow timely initiation of anticoagulation therapy for the prevention of stroke, the European guidelines on atrial fibrillation (AF) recommend the monitoring of AHRE progression along pre-specified strata (6min…&lt;1h, 1h…&lt;24, ≥24h). We sought to assess the capability of a single-lead implantable cardioverter defibrillator (ICD), that is equipped with an atrial dipole for atrial sensing, to remotely detect and monitor AHRE burden progression in patients with standard indication to single-chamber ICD.

Methods

From the MATRIX (Management and Detection of Atrial Tachyarrhythmias in Patients Implanted With BIOTRONIK DX Systems) registry, we analyzed remotely transmitted, and electrogram (IEGM) AHREs in a subset of patients with remote transmissions and without history of long-standing AF at baseline. For each patient, we selected the first occurring episode per duration stratum and the first subsequent occurrence when progressing to a stratum of any longer duration. After episode adjudication by an independent electrophysiologist, we assessed the classification performance of the device (positive predictive value [PPV]) and analyzed AHRE onset and progression pathways.

Results

Of the MATRIX cohort, 1,746 patients matched the inclusions criteria (see table for patient characteristics) and 1,451 had no AF history. Of the 258 patients with AHREs (14.8%), 450 out of 465 evaluated episodes were correctly classified as AHRE. Reasons for misclassification were artifact (13) and R-wave oversensing (2). PPV was 96.8% (95% confidence interval 94.7%-98.2%). Grouped by stratum, PPV was 93.9%, 99.5% and 100% for 6min…&lt;1h, 1h…&lt;24 and ≥24h, respectively. Ninety six of 240 patients (40.0%) with a first episode according to the pre-specified strata were progressing to a stratum of longer duration and 9 patients (3.8%) had further progression (see Figure). In 119 out of 1,451 patients without AF history (8.2%), the device detected AHRE and 81 of them (4.6% of analysis set) had a mid to high risk for stroke and were not on anticoagulation therapy. In 121 out of 295 patients with known history of paroxysmal and persistent AF (41.0%), the arrhythmia was confirmed by the device.

Discussion and Conclusion: The single-chamber ICD with atrial sensing capabilities correctly classified ≈97% of all adjudicated AHREs ≥6min. About 7% of patients had device-detected AHRE onset and/or progression and a mid to high stroke risk. These patients would potentially benefit the most from a guideline-conform AF monitoring strategy to timely initiate anticoagulation medication for stroke prevention.

Ribonucleotide reductase, a novel drug target for gonorrhea

Antibiotic-resistant Neisseria gonorrhoeae (Ng) are an emerging public health threat due to increasing numbers of multidrug resistant (MDR) organisms. We identified two novel orally active inhibitors, PTC-847 and PTC-672, that exhibit a narrow spectrum of activity against Ng including MDR isolates. By selecting organisms resistant to the novel inhibitors and sequencing their genomes, we identified a new therapeutic target, the class Ia ribonucleotide reductase (RNR). Resistance mutations in Ng map to the N-terminal cone domain of the α subunit, which we show here is involved in forming an inhibited α4β4 state in the presence of the β subunit and allosteric effector dATP. Enzyme assays confirm that PTC-847 and PTC-672 inhibit Ng RNR and reveal that allosteric effector dATP potentiates the inhibitory effect. Oral administration of PTC-672 reduces Ng infection in a mouse model and may have therapeutic potential for treatment of Ng that is resistant to current drugs.

Outcomes after reperfusion therapies in patients with ACA stroke: A multicenter cohort study from the EVATRISP collaboration

BACKGROUND

Patients with stroke secondary to occlusions of the anterior cerebral artery (ACA) often have poor outcomes. The optimal acute therapeutic intervention for these patients remains unknown.

METHODS

Patients with isolated ACA-stroke were identified from 10 centers participating in the EndoVascular treatment And ThRombolysis in Ischemic Stroke Patients (EVATRISP) prospective registry. Patients treated with endovascular thrombectomy (EVT) were compared to those treated with intravenous thrombolysis (IVT). Odds ratios with 95% confidence intervals (OR; 95%CI) were calculated using multivariate regression analysis.

RESULTS

Included were 92 patients with ACA-stroke. Of the 92 ACA patients, 55 (60%) were treated with IVT only and 37 (40%) with EVT (±bridging IVT). ACA patients treated with EVT had more often wake-up stroke (24% vs. 6%, p = 0.044) and proximal ACA occlusions (43% vs. 24%, p = 0.047) and tended to have higher stroke severity on admission [NIHSS: 10.0 vs 7.0, p = 0.054). However, odds for favorable outcome, mortality or symptomatic intracranial hemorrhage did not differ significantly between both groups. Exploration of the effect of clot location inside the ACA showed that in patients with A1 or A2/A3 ACA occlusions the chances of favorable outcome were not influenced by treatment allocation to IVT or EVT.

DISCUSSION

Treatment with either IVT or EVT could be safe with similar effect in patients with ACA-strokes and these effects may be independent of clot location within the occluded ACA.

Risks of Undersizing Stent Retriever Length Relative to Thrombus Length in Patients with Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Results regarding the association of thrombus length, stent retriever length, and recanalization success in patients with acute ischemic stroke are inconsistent. We hypothesized that the ratio of thrombus length to stent retriever length may be of particular relevance.

MATERIALS AND METHODS

Patients with acute ischemic stroke undergoing stent retriever thrombectomy at our institution between January 2010 and December 2018 were reviewed retrospectively. Thrombus length was assessed by measuring the susceptibility vessel sign on SWI using a 1.5T or 3T MR imaging scanner. Multivariable logistic regression models were used to determine the association between thrombus length, stent retriever length, and thrombus length/stent retriever length ratio with first-pass recanalization, overall recanalization, and embolization in new territories. Results are shown as adjusted ORs with 95% CIs. Additional mediation analyses were performed to test for indirect effects on first-pass recanalization and overall recanalization success.

RESULTS

The main analysis included 418 patients (mean age, 74.9 years). Increasing stent retriever length was associated with first-pass recanalization. Decreasing thrombus length and lower thrombus length/stent retriever length ratios were associated with first-pass recanalization and overall recanalization. Thrombus length and stent retriever length showed no association with first-pass recanalization or overall recanalization once thrombus length/stent retriever length ratio was factored in, while thrombus length/stent retriever length ratio remained a significant factor in both models (adjusted OR, 0.316 [95% CI, 0.112-0.892]; P = .030 and adjusted OR, = 0.366 [95% CI, 0.194-0.689]; P = .002). Mediation analyses showed that decreasing thrombus length and increasing stent retriever length had a significant indirect effect on first-pass recanalization mediated through thrombus length/stent retriever length ratio. The only parameter associated with embolization in new territories was an increasing thrombus length/stent retriever length ratio (adjusted OR, 5.079 [95% CI, 1.332-19.362]; P = .017).

CONCLUSIONS

Information about thrombus and stent length is more valuable when combined. High thrombus length/stent retriever length ratios, which may raise the risk of unsuccessful recanalization and embolization in new territories, should be avoided by adapting stent retriever selection to thrombus length whenever possible.

High-degree atrioventricular block after valve-in-valve transcatheter aortic valve implantation: incidence and predictors

Background

High-degree atrioventricular (AV) block and permanent pacemaker (PPM) implantation represent major complications after transcatheter aortic valve implantation (TAVI). Data on the incidence of AV block for patients undergoing valve-in-valve (ViV) TAVI are scarce. We examined the incidence and predictors of periinterventional AV conduction disturbances in a cohort of subjects undergoing ViV TAVI compared to subjects undergoing TAVI of native aortic valves.

Methods

In 50 consecutive patients who underwent ViV TAVI, clinical characteristics, incidence and predictors for AV conduction disturbances as well as intrahospital outcome were assessed. Applying a matched pair approach for age, gender, type and size of transcatheter valve, these subjects were compared to 50 patients undergoing TAVI of native tricuspid aortic valves.

Results

Mean age in both groups was 80±6 years and 50% of subjects were male. In the ViV group, 22 patients (44%) had a stented bioprosthesis, 10 patients (20%) a stentless bioprosthesis and 18 patients (36%) a previous TAVI prosthesis (balloon-expandable: n=15, self-expandable n=3). The majority of subjects (92% in each group) were treated using balloon-expandable valves (ViV group: Sapien XT, n=20 or Sapien 3, n=26, control group: Sapien XT, n=19 or Sapien 3, n=27).

Periinterventional, non-reversible 3rd degree AV-block occurred in 6 patients within each group (12%), and all of the affected patients underwent PPM implantation. Among the 32 patients who underwent ViV-TAVI of a surgically placed bioprosthesis, only 2 (6%) developed a high-degree AV block (1/22 with a stented bioprosthesis and 1/10 with a stentless bioprosthesis). In contrast, high-degree AV block occurred in 4/18 patients (22%) who underwent ViV TAVI of a prior TAVI prosthesis. There was a significant difference in the occurrence of total high-degree AV blocks requiring postinterventional PPM implantation (p=0.033) between subjects who received TAVI of stented bioprostheses and those who received re-TAVI.

In logistic regression analysis, pre-existing RBBB represented a significant predictor for periinterventional 3rd degree AV block across the whole cohort (p=0.001, Exp(B)=10.667), both in ViV subjects (p=0.016, Exp(B)=12.0) and in the control group (p=0.018, Exp(B)=10.0).

Conclusion

Periinterventional AV block occurs infrequently in subjects undergoing ViV TAVI for treatment of degenerated surgical bioprostheses. However, patients undergoing ViV TAVI for degenerated transcatheter prostheses as well as subjects with pre-existing RBBB are at substantial risk for the occurence of AV block and require close peri-interventional monitoring.

Funding Acknowledgement

Type of funding sources: None.

Localization of the femoral artery bifurcation: hips don't lie – in at least 97% of cases

Background

The most common vascular access for structural cardiac interventions such as transcatheter aortic valve implantation (TAVI) is the common femoral artery (CFA). Depending on the procedure CFA puncture has to be performed not only unilaterally, but also bilaterally. Since incorrect localization of femoral access can lead to severe vascular complications, specific knowledge about the exact position of the CFA bifuraction is helpful. Such information might be systematically obtained from pre-TAVI CT scans.

Methods

We performed a retroperspective analysis of consecutive contrast-enhanced pre-TAVI CT angiography data sets (n=1000) to determine the CFA bifurcation localization relative to the femoral head and the correlation to contralateral CFA bifurcation location.

Results

The site of the CFA bifurcation was in 67.2% below the femoral head (−−), in 24.3% within the lower third of the femoral head (−), in 7.4% in the mid (0) and in 1.2% within the upper third (+) of the femoral head. Bifurcations above (++) the femoral head were not detected. CFA bifurcations below the femoral head showed the highest prevalence within men and women in all age groups (50–59, 60–69, 70–79, 80–89, 90–99 years). Bilateral agreement of CFA bifurcations was observed in only 69.3% and was independent of one-sided hip replacement (agreement 72.7%) or two-sided hip replacement (agreement 78.7%). A congruent contralateral left CFA bifurcation below the femoral head could be predicted in 80.6%, whereas CFA bifurcations within the lower and upper margins of the femoral head were congruent in only 65.7% (of these, 49.2% for the lower third, 29.7% for the mid and 36.4% for the upper third).

Conclusion

In conclusion, punctures within the upper third of the femoral head will provide an ideal puncture site in at least 97% of cases, independent of age, sex, or previous hip replacement.

Funding Acknowledgement

Type of funding sources: None.

Impact of COVID-19 lockdown on the procedural and intra-hospital outcome of STEMI patients

Background

While during the COVID-19 pandemic the number of patients presenting with ST-segment elevation myocardial infarction (STEMI) decreased, no change in patient or system delay could be shown due to local lockdown (LD) policy. Not much is known about the influence of LD on procedural details and intrahospital outcome of these patients.

Methods

Data was obtained from 511 patients treated for acute STEMI (24hours from symptom onset) from January 2019 to March 8th 2021 at two primary PCI (pPCI) centers in Germany. Patients presenting as intra-hospital STEMI, patients showing no culprit lesion and patients undergoing direct CABG were excluded. Overall, 456 patients (74% male, mean age 64±12) were included. These patients were divided into two groups: complete lockdown (LD; n=58; March 21st–April 20th 2020 and December 16th 2020–March 7th 2021) and no complete lockdown (No-LD; n=398)).

Results

There were no differences in pre-hospital care between the groups: Telemedicine (LD 23.5% vs. No-LD 34.9%; p=0.11), pre-alarm of the cath-lab staff (LD 59.6% vs. 66.6%, p=0.32) and direct admission to the cath-lab (LD 44.8% vs. No-LD 49.8%, p=0.58) were performed as often as in No-LD times. Neither the pain to first medical contact (LD 188±272 Min vs. No-LD 236±317 Min, p=0.29) nor the door to balloon time (55±54 Min vs. No-LD 49±58 Min, p=0.470) as well as other periods showed any difference.

All over cardio-pulmonary resuscitation (CPR; LD 19.0% vs. No-LD 14.3%, p=0.35) or presentation with cardiogenic shock (25.9% vs 23.9%, p=0.74) was equally presented in both groups. However, left ventricular assist devices were implanted more often during LD (6.9% vs. No-LD 1.8%; p=0.017).

Primary radial access was performed in the majority of the cases (LD 60.3% vs. No-LD 58.8%, p=0.82). During LD the culprit lesion was RCA in most cases (46.6% vs. No-LD LAD 46.7%, p=0.341). Stent thrombosis was not more common in out-of-hospital STEMI patients during LD (6.9% vs. 8.0%, p=0.76). Thrombus aspiration was performed in 10.3% during lockdown (vs. No-LD 4.5%, p=0.06), GP-IIb-IIIa inhibitors were not administered more often (LD 19.0% vs. No-LD 19.4%, p=0.92) and no reflow phenomenon was not seen more frequent (LD 20.7% vs. No-LD 21.3% p=0.91). TIMI III flow could be established in the majority of the cases (LD 86.0% vs. No-LD 91.5%, p=0.20).

During further hospital stay, neither the frequency of ventilator (LD 17.2% vs. No-LD 17.0%, p=0.98) nor vasopressor use (LD 20.7% vs. No-LD 20.1% p=0.925) differed. Left ventricular function (47±13% vs. No-LD 45±12%; p=0.34) and maximum creatinkinase (LD 1827±1687 U/l vs. No-LD: 2292±4100 U/l, p=0.40) showed no difference between the groups as did intrahospital death (LD 10.3% vs. No-LD 11.6%, p=0.79).

Conclusion

Despite the known decline in STEMI patients during LD periods, patient care, procedural details and inta-hospital outcome of the ones presenting to a pPCI hospital do not change during LD periods.

Funding Acknowledgement

Type of funding sources: None.

SWI Susceptibility Vessel Sign in Patients Undergoing Mechanical Thrombectomy for Acute Ischemic Stroke

BACKGROUND AND PURPOSE

The frequency and clinical significance of the susceptibility vessel sign in patients with acute ischemic stroke remains unclear. We aimed to assess its prevalence in patients with acute ischemic stroke undergoing mechanical thrombectomy and to analyze its association with interventional and clinical outcome parameters in that group.

MATERIALS AND METHODS

Six hundred seventy-six patients with acute ischemic stroke and admission MR imaging were reviewed retrospectively. Of those, 577 met the eligibility criteria for further analysis. Imaging was performed using a 1.5T or 3T MR imaging scanner. Associations between baseline variables, interventional and clinical outcome parameters, and susceptibility vessel sign were determined with multivariable logistic regression models. Results are shown as adjusted ORs with 95% CIs.

RESULTS

The susceptibility vessel sign was present in 87.5% (n = 505) of patients and associated with tandem occlusion (adjusted OR, 3.3; 95% CI, 1.1-10.0; P = .032) as well as successful reperfusion, defined as an expanded TICI score of ≥2b (adjusted OR, 2.4; 95% CI, 1.28-4.6; P = .007). The susceptibility vessel sign was independently associated with functional independence (mRS ≤ 2: adjusted OR, 2.1; 95% CI, 1.1-4.0; P = .028) and lower mortality (adjusted OR, 0.4; 95% CI, 0.2-0.7; P = .003) at 90 days, even after adjusting for successful reperfusion. The susceptibility vessel sign did not influence the number of passes performed during mechanical thrombectomy, the first-pass reperfusion, or the risk of peri- or postinterventional complications.

CONCLUSIONS

The susceptibility vessel sign is an MR imaging phenomenon frequently observed in patients with acute ischemic stroke and is associated with successful reperfusion after mechanical thrombectomy. However, superior clinical functional outcome and lower mortality noted in patients showing the susceptibility vessel sign could not be entirely attributed to higher reperfusion rates.

Neurons populating the rectal extrinsic nerves in humans express neuronal and Schwann cell markers

BACKGROUND

In mice, Schwann cell (SC) progenitors give rise to autonomic ganglion cells and migrate into the gut to become enteric neurons. It is unknown whether SC progenitors have a similar fate in humans. In search of evidence for human SC-derived neurogenesis in the gastrointestinal (GI) tract, we studied the rectums from cadaveric controls and children with anorectal malformations (ARM).

METHODS

We analyzed distal rectal tissue taken at autopsy from 10 children with normal GI tracts and resected rectal specimens in 48 cases of ARM. Of these specimens, 6 had neurons within the extrinsic rectal innervation. These were further investigated with immunohistochemistry for neuronal and SC/glial markers.

KEY RESULTS

Perirectal tissue from control and ARM contained GLUT1-positive extrinsic nerves, many containing neurons. SC/glial markers (SOX10, CDH19, and PLP1) were expressed by glia in the enteric nervous system and perirectal nerves, while MPZ predominated only in glia of perirectal nerves, in both control and ARM. Neurons in perirectal nerves were 61% larger in ARM samples and co-expressed SOX10 (81%), PLP1 (73%), and CDH19 (56%). In ARM, cytoplasmic SOX10 was co-expressed with neuronal antigens in ~57% of submucosal and myenteric neurons, vs. ~3% in control. Furthermore, intrinsic gut neurons in ARM specimens co-expressed PLP1 (18%) and CDH19 (18%); however, neuronal co-expression of PLP1 and CDH19 was rarely (<2%) observed in controls.

CONCLUSIONS & INFERENCES

Dual expression of glial and neuronal markers in rectal and perirectal neurons support a model of Schwann cell-derived neurogenesis in the innervation of the human GI tract.

The internet as non-biomedical milieu: Production of alternative health techno-social spaces and the persistence of marginalised medical practices

This paper describes how spatial understandings of the internet (i.e. the internet is a 'space') enable the persistence of marginalised medical practices. By tracing different accounts of the internet as space among practitioners and followers of diện chẩn - an emergent Vietnamese unregulated therapeutic method - we show how the logic of space circumscribes an alternative techno-social site for marginalised medical practices, transforms the private experience of being alone with technology into being-in-space, spiritualises the internet as a conduit of healing power, and mediates transnational health mobility among the Vietnamese diaspora. Drawing on interviews and ethnographic participation in Vietnam and the US, we demonstrate how the internet can be understood as non-biomedical milieu - a field of determination that conjoins heterogenous interventions on health-related eventualities outside of structured and institutionalised biomedical practices. This in vivo conceptualisation of the internet as space offers a point of convergence against the bifurcation of information as abstract and technology as concrete. A spatial conceptualisation highlights the embeddedness of health knowledge on the internet and shows how techno-social interrelations produce different spaces of multiplicity, which constitute a favourable milieu for medical practices outside of the biomedical institution to persist.

Experimental study on the influence of model variations on the airway occlusion of an obstructive sleep apnea patient

This study deals with the analysis of model parameters to mimic the airway collapse of an obstructive sleep apnea patient during nasal breathing. Different material properties and geometry variations of a patient-specific airway model are analyzed in detail. The patient-specific airway geometry is obtained from MRI data. A completely rigid model is compared to two partly elastic variations with different elasticities. Furthermore, the influence of the nasal cavities and the treatment effect of a mandibular protrusion are studied. Rigid model parts are 3D-printed and elastic parts cast from silicone. The models are analyzed under the impact of a transient airflow which is realized through a computer controlled piston pump. The results suggest, that, for moderate deformations, the elasticity of the soft tissue replicate influences rather the level of the pressure drop inside the airway than the shape of the pressure curve. The same suggestion can be made for the influence of the nasal cavities. Often, the spatial location of the minimum pressure is taken as the collapse site of the airway geometry. This study demonstrates, that the spatial locations of the minimum pressure and the maximum deformation do not match. This reveals the importance of a coupled approach of soft tissue and airflow analysis in the search of the collapse site and therefore the best treatment option. A treatment effect of the mandibular protrusion can be anticipated with an accurate patient-specific airway model.

The Implementation and Effectiveness of PathElective.com

The COVID-19 pandemic put most in-person pathology electives on-hold as departments adapted to changes in education and patient care. To address the subsequent void in pathology education, we created a free, virtual, modular, and high-quality pathology elective website. Website traffic from June 1, 2020, to October 1, 2020, was monitored using the built-in analyses on Squarespace. Twitter engagement was analyzed using Twitter analytics and the Symplur Social Graph Score. A voluntary satisfaction survey was sent to all PathElective users and results were analyzed. During this time, the site saw 25 467 unique visitors, over 34 988 visits, 181 302 page views, and 4449 subscriptions from 99 countries. Countries with the highest traffic are the United States (14 682), India (5210), and the Philippines (2195). PathElective’s Twitter social graph score increased from 63.59 to 89.3 with the addition of 1637 followers. Data from surveyed users (n = 177) show most to be pathology residents (41%). Most subscribers (89%) are committed to a career in pathology. The majority heard of the website via Twitter (55%). Almost half of those surveyed engaged with the PathTwitter community on Twitter and of those who participated, 99% found that interaction useful. In all survey questions surrounding satisfaction and usefulness, a large majority of the users were either satisfied or very satisfied. PathElective is a novel pathology elective that offers a unique opportunity to educate medical students and residents from around the globe and demonstrates high effectiveness and satisfaction among users.