Submicron and Nanometer Structures Technology and Research

Contains reports on sixteen research projects and a list of publications.Joint Services Electronics Program Contract DAAL03-89-C-0001Joint Services Electronics Program Contract DAAL03-92-C-0001National Science Foundation Grant ECS 90-16437Semiconductor Research Corporation Contract 90-SP-080U.S. Navy - Naval Research Laboratory Contract N00014-90-K-2018IBM CorporationU.S. Air Force - Office of Scientific Research Grant F49620-92-J-0064National Science Foundation Grant DMR 87-19217National Science Foundation Grant DMR 90-22933National Aeronautics and Space Administration Contract NAS8-36748National Aeronautics and Space Administration Grant NAGW-2003National Science Foundation Grant DMR 90-01698Spire Corporatio

Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.

BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden

A Rare but Morbid Neurosurgical Target: Petrous Aneurysms and Their Endovascular Management in the Stent/Flow Diverter Era

Background/objective The rarity of petrous internal carotid artery (ICA) aneurysms has largely precluded analyses of their presentation and management in case series format. Methods We performed a retrospective analysis of our endovascular database of patients treated from January 2001 to May 2016 to identify patients with petrous ICA aneurysms. We evaluated the treatment approach and results for patients managed in the era of dedicated intracranial stents and flow diverters, noting clinical and angiographic results. Results Our database search identified 10 patients with petrous ICA aneurysms. Six aneurysms were managed in the era of dedicated intracranial stents and flow diverters. Two patients presented with cranial nerve palsies, two with incidental but enlarging aneurysms that had completely eroded through the petrous bone, one with transient ischemic attacks, and one with pulsatile tinnitus. Five aneurysms were large and one was small but symptomatic. In three cases the aneurysm was treated by flow diversion with adjunctive coiling; two patients with at least 4-month follow-up had complete occlusion of their aneurysm and significant improvement of mass effect symptoms. In one case the aneurysm was treated with balloon-assisted coiling with resultant near-complete occlusion. In two cases, prior to the introduction of flow diverters, the aneurysm was treated via stent-assisted coiling with resultant near-complete obliteration; one patient had resolution of pretreatment pulsatile tinnitus. There were no intraprocedural or postprocedural complications; no patients underwent retreatment. Conclusions Endovascular treatment of large or symptomatic petrous ICA aneurysms, in the era of flow diversion, is associated with excellent angiographic and clinical outcomes

70 Surgical outcomes for robotic-assisted single-site hysterectomy as compared to multi-site hysterectomy: a single institution retrospective study

Objectives: Robotic-assisted minimally invasive surgery is considered safe and effective in gynecologic oncology. While traditional multi-site robotic surgery remains the standard, single-site robotic surgery is often thought to have additional benefits related to cos-mesis, length of hospital stays, and other perioperative outcomes. However, comparison studies between the two surgical approaches are lacking. The purpose of this study is to assess the surgical outcomes of robotic-assisted single-site hysterectomy (SSH) as compared to multi-site hysterectomy (MSH). Methods: Patients who underwent SSH and MSH from October 2013–June 2022 at a single institution were identified using case log data from the daVinci® Surgical System. Clinical data regarding preoperative, intraoperative, and postoperative variables were then extrapolated from the electronic medical record for analysis using logistic regression for binary outcomes and linear regression for continuous outcomes. Propensity score matching using a 1:1 model was conducted as sensitivity analysis. Results: A total of 572 patients met inclusion criteria, with 127 undergoing SSH and 445 undergoing MSH. When comparing SSH with MSH, median operative times were 118 minutes for SSH versus 162 minutes for MSH (p<0.001). The plurality (47%) of SSH patients had estimated blood loss of <50 mL compared to 50-99 mL for the plurality (36%) of MSH patients. 23% of SSH patients were discharged on the day of surgery compared to only 8% of MSH patients (p<0.001). The maximum length of postoperative admission was 3 days for SSH patients and 8 days for MSH. There were no statistically significant differences seen between SSH and MSH when comparing rates of conversion to laparotomy or ED presentation, readmission, reoperation, postoperative infection, vaginal cuff dehiscence, urinary tract or bowel injury, ileus, or small bowel obstruction within 30 days postoperatively. These results were consistent in the sensitivity analysis. Conclusions: SSH has overall good outcomes including decreased operative times, lower amounts of blood loss, and decreased lengths of postoperative hospital stays when compared to MSH. Given these benefits, SSH may be a surgical modality with utility in gynecologic oncology patients

Balloon remodeling of complex anterior communicating artery aneurysms: technical considerations and complications

INTRODUCTION: Reports of the limitations and feasibility of balloon remodeling for treatment of complex anterior communicating artery (ACoA) aneurysms are scarce. METHODS: Ninety-nine patients were treated with balloon-assisted coil embolization for ACoA aneurysms between August 2004 and October 2012. Records were reviewed for aneurysm characteristics, balloon trajectory (vessel and side), bilateral access, treatment-related complications, and aneurysm recurrence determined by magnetic resonance angiography (MRA). Morphological outcomes following treatment were categorized into Raymond class I, II, or III. RESULTS: Fifty-three aneurysms (53.5%) were unruptured and 46 (46.4%) were ruptured. Aneurysmal occlusion (Raymond I or II) was achieved in 89 patients (89.9%); three (3.0%) were incompletely embolized and treatment was aborted in six (6.1%). Balloon trajectories were from the A1 to either the ipsilateral or contralateral A2. In 17 cases (17.2%), bilateral A1 access was used to achieve balloon protection of the contralateral A2. In four cases (4.0%), balloon remodeling was aborted due to technical difficulty. There were 15 (15.2%) treatment-related complications; five (5.1%) were intraoperative ruptures, one of which resulted in a neurological deficit and another in death. All other complications were clinically silent, producing a permanent complication rate of 2.0%. Mean radiographic follow-up was 2.5 years, and six patients (6.1%) were retreated for recurrence or known remnant. CONCLUSIONS: Balloon remodeling should be considered for broad-based complex ACoA aneurysms. This technique provides a high rate of aneurysm occlusion with an acceptable complication profile, and avoids the need for dual antiplatelet therapy. The balloon trajectory will depend on aneurysm morphology and bilateral access may be useful in selected cases

Endovascular Treatment of Previously Clipped Aneurysms: Continued Evolution of Hybrid Neurosurgery

Background/objective The optimal management of residual or recurrent clipped aneurysms is infrequently addressed in the literature. Methods We reviewed our endovascular database from January 1998 to May 2016 to identify patients with clipped aneurysms undergoing subsequent endovascular treatment, evaluating treatment approach, and clinical and angiographic outcomes. Results 60 patients underwent endovascular treatment of residual/recurrent clipped aneurysms; 7 rebled prior to endovascular therapy. Treatment was via coiling alone (n=25, 42%), stent assisted coiling (n=15, 25%), balloon assisted coiling (n=8, 13%), flow diversion (n=8, 13%), stenting alone (n=3, 5%), or flow diversion with coiling (n=1, 2%). The procedural permanent neurological morbidity and mortality rates were 3% and 2%, respectively. Over a clinical follow-up of 253.4 patient years (median 3.9 years), there was one rebleed in a patient who had declined further treatment. For 43 patients with at least 1 month of digital subtraction angiographic follow-up (median 3.4 years), complete aneurysm occlusion was seen in 79% of cases. Neck remnants were observed in 14%, and stable small dome remnants were observed in 7% of cases. In a subgroup of 18 patients with \u27clip induced\u27 narrow neck aneurysms, all domes were initially coil occluded (Raymond 1 or 2); there was no permanent procedural morbidity and no aneurysms required retreatment or recanalized over a median follow-up of 3.9 years. Conclusions Endovascular treatment of residual or recurrent clipped aneurysms is an excellent treatment approach in well selected patients; \u27clip induced\u27 narrow neck aneurysms fare particularly well after treatment both angiographically and clinically

Incidence of delivery wire recapture failure with the Pipeline Flex device

BACKGROUND: The Pipeline Flex embolization device has several advantages over the first-generation Pipeline embolization device (Covidien, Dublin, Republic of Ireland). Despite these advantages, we have observed frequent difficulty in recapturing the device\u27s delivery wire. OBJECTIVE: To prospectively document the incidence of failure to recapture the delivery wire. METHODS: We tracked our experience in patients undergoing endovascular treatment with a flow-diverting stent for cerebral aneurysms between 1 May and 30 September 2016. Patient and lesion characteristics, device dimensions, and technical outcomes of delivery wire recapture were prospectively recorded for each device. RESULTS: Eighteen devices were deployed in 15 patients by the senior author (FCA) during this period. Failure to recapture the delivery wire occurred in 10 of 18 (56%) cases. No adverse outcomes of delivery wire recapture failure were encountered in this series. CONCLUSIONS: The incidence of delivery wire recapture failure with the Pipeline Flex device is high. Failure to recapture the delivery wire carries a theoretical risk of stent displacement when re-navigating across the device, and endovascular surgeons should be aware of this limitation. Authors are encouraged to report delivery wire recapture failure rates in future clinical series in which the Pipeline Flex device is used

Resolution of cranial neuropathies following treatment of intracranial aneurysms with the Pipeline Embolization Device

OBJECT: Intracranial aneurysms, especially those of the cavernous segment of the internal carotid artery (ICA), can present with cranial nerve (CN) palsies. The Pipeline Embolization Device (PED) has demonstrated safety and efficacy in the treatment of cerebral aneurysms by flow diversion, but little data exist reporting the outcomes of cranial neuropathies following treatment with the device. METHODS: The prospectively maintained Barrow Neurological Institute\u27s endovascular database was reviewed for all patients treated with the PED after presenting with one or more CN palsies secondary to a cerebral aneurysm since May 2011. Patient charts and digital subtraction angiograms were reviewed to report clinical and angiographic outcomes. Only patients with clinical follow-up were included in the analysis. RESULTS: A total of 127 patients were treated with the PED at the authors\u27 institution after FDA approval. Twentytwo patients presented with cranial neuropathies, for initial inclusion in this study. Of these, 20 had sufficient followup for analysis. Cranial neuropathies included those of CN II, III, V, and VI, with presenting symptoms of diplopia, decreased visual acuity, and facial numbness and/or pain. Thirteen lesions were cavernous segment ICA aneurysms, whereas the remainder included supraclinoid and petrous segment ICA, posterior communicating artery, and basilar trunk aneurysms. At an average clinical follow-up of 9.55 months, 15 patients (75%) had resolution or significant improvement of their cranial neuropathies, and the remaining 5 had stable symptoms. Of the 18 patients with angiographic follow-up, 12 (66.7%) demonstrated complete obliteration or small neck residual, whereas 6 (33.3%) had residual lesion. Patients with complete or near-complete obliteration of their lesion were significantly more likely to demonstrate symptomatic improvement at follow-up (p = 0.009). Two patients with persistent symptoms were eventually treated with microsurgical bypass. Transient complications in this series included 6 (30%) extracranial hemorrhagic complications related to dual-antiplatelet therapy, all of which were managed medically. There was 1 delayed right ICA occlusion following retreatment that led to microsurgical bypass. CONCLUSIONS: Intracranial aneurysms presenting with one or more CN palsies show a high rate of clinical improvement after treatment with the PED. Clinical outcomes must be weighed against the risks and challenges faced with flow diverters. Further research is warranted for patients whose symptoms do not respond optimally to device placement

Resolution of cranial neuropathies following treatment of intracranial aneurysms with the Pipeline Embolization Device

OBJECT: Intracranial aneurysms, especially those of the cavernous segment of the internal carotid artery (ICA), can present with cranial nerve (CN) palsies. The Pipeline Embolization Device (PED) has demonstrated safety and efficacy in the treatment of cerebral aneurysms by flow diversion, but little data exist reporting the outcomes of cranial neuropathies following treatment with the device. METHODS: The prospectively maintained Barrow Neurological Institute\u27s endovascular database was reviewed for all patients treated with the PED after presenting with one or more CN palsies secondary to a cerebral aneurysm since May 2011. Patient charts and digital subtraction angiograms were reviewed to report clinical and angiographic outcomes. Only patients with clinical follow-up were included in the analysis. RESULTS: A total of 127 patients were treated with the PED at the authors\u27 institution after FDA approval. Twentytwo patients presented with cranial neuropathies, for initial inclusion in this study. Of these, 20 had sufficient followup for analysis. Cranial neuropathies included those of CN II, III, V, and VI, with presenting symptoms of diplopia, decreased visual acuity, and facial numbness and/or pain. Thirteen lesions were cavernous segment ICA aneurysms, whereas the remainder included supraclinoid and petrous segment ICA, posterior communicating artery, and basilar trunk aneurysms. At an average clinical follow-up of 9.55 months, 15 patients (75%) had resolution or significant improvement of their cranial neuropathies, and the remaining 5 had stable symptoms. Of the 18 patients with angiographic follow-up, 12 (66.7%) demonstrated complete obliteration or small neck residual, whereas 6 (33.3%) had residual lesion. Patients with complete or near-complete obliteration of their lesion were significantly more likely to demonstrate symptomatic improvement at follow-up (p = 0.009). Two patients with persistent symptoms were eventually treated with microsurgical bypass. Transient complications in this series included 6 (30%) extracranial hemorrhagic complications related to dual-antiplatelet therapy, all of which were managed medically. There was 1 delayed right ICA occlusion following retreatment that led to microsurgical bypass. CONCLUSIONS: Intracranial aneurysms presenting with one or more CN palsies show a high rate of clinical improvement after treatment with the PED. Clinical outcomes must be weighed against the risks and challenges faced with flow diverters. Further research is warranted for patients whose symptoms do not respond optimally to device placement