O-EGS08 Endoluminal Vacuum Therapy (EVT) for leaks in the upper gastrointestinal (UGI) tract; 10-years’ experience in a specialist Oesphagogastric centre

Background Endoluminal vacuum therapy (EVT) is an emerging treatment strategy for UGI leaks. When compared to traditional treatments strategies EVT is reported to reduce morbidity and mortality, especially in patients with delayed presentation and established sepsis. We report the outcomes for patients with UGI leaks and perforations treated with EVT using an ad-hoc endoluminal vacuum device (EVD) in a tertiary UK hospital over a 10-year period. Methods Sixty-seven patients with UGI leaks from disparate causes were treated with EVT between April 2011 and July 2021. The ad-hoc EVD was constructed using a piece of open cell foam sutured around the distal end of a nasogastric tube, and placed endoscopically either through the perforation and into the extra-luminal leak cavity OR intraluminally depending on the morphology of the leak cavity. Continuous negative pressure (125mmHg) was applied. Endoscopic re-evaluation of the leak cavity with change of EVD was performed every 48-120 hours depending on the patients clinical condition. Information related to treatment and outcome was recorded prospectively. Results Patients had a median age of 66 years (range 23-92), and median Apache II score of 21 (range 4-36) at presentation. Fifty-two leaks were oesophageal (78%), 12 gastric (18%), 2 duodenal (3%), and 1 pharangeal (1%). The leak cause was anastomotic in 26 (39%), iatrogenic in 20 (30%), spontaneous in 19 (28%), and traumatic in 2 (3%). The median number of EVD changes required to heal the leak was 6 (range 1-27), and median length of hospital stay was 42 days (range 1-182). Successful resolution of the leak was achieved in 59 patients (88%). Eight (12%) patients died during treatment. There were no complications related to insertion of the EVD. Conclusions EVT is an effective treatment for UGI leaks which can be delivered safely in a tertiary oesophagogastric centre, and used to treat a wide range of leak causes in critically unwell patients. Further studies are required to develop a standardized procedure to improve the ease with which EVT can be delivered. This will enable broader adoption of EVT for this group of patients.

Broadband and Integratable 2 × 2 TWT Amplifier Unit for Millimeter Wave Phased Array Radar

A novel power amplifier unit for a phased array radar with 2 × 2 output ports for a vacuum electron device is proposed. Double parallel connecting microstrip meander-lines are employed as the slow-wave circuits of a large power traveling wave tube operate in a Ka-band. The high frequency characteristics, the transmission characteristics, and the beam–wave interaction processes for this amplifier are simulated and optimized. For each output port of one channel, the simulation results reveal that the output power, saturated gain, and 3-dB bandwidth can reach 566 W, 27.5 dB, and 7 GHz, respectively. Additionally, the amplified signals of four output ports have favorable phase congruency. After fabrication and assembly, transmission tests for the 80-period model are performed preliminarily. The tested “cold” S-parameters match well with the simulated values. This type of integratable amplifier combined with a vacuum device has broad application prospects in the field of high power and broad bandwidth on a millimeter wave phased array radar.

Ultrafast High-Voltage Kicker System for Ion-Clearing Gaps

Ionization scattering of electron beams with residual gas molecules causes ion trapping in electron rings, both in a collider and electron cooling system. These trapped ions may cause emittance growth, tune shift, halo formation, and coherent coupled bunch instabilities. In order to clear the ions and prevent them from accumulating turn after turn, the gaps in a temporal structure of the beam are typically used. Typically, the gap in the bunch train has a length of a few percent of the ring circumference. In those regions, the extraction electrodes with high pulsed voltages are introduced. In this paper, we present the design consideration and initial test results of the high-voltage pulsed kicker hardware that includes vacuum device and pulsed voltage driver, capable of achieving over 3 kV of deflecting voltage amplitude, rise and fall times of less than 10 ns, 100 ns flat-top duration at 1.4 MHz repetition rate.

698 ENDOLUMINAL VACUUM THERAPY (EVT) AS A TREATMENT FOR ESOPHAGEAL LEAKS; 10-YEARS’ EXPERIENCE FROM A TERTIARY UK ESPHAGOGASTRIC CENTRE

Esophageal leaks present a significant management challenge, especially in patients with delayed presentation and established sepsis. Endoluminal vacuum therapy (EVT) is an emerging treatment strategy which may reduce morbidity and mortality compared to traditional treatments in this patient group. We report the outcomes for patients with esophageal leaks from a range of different causes that were treated with EVT in a tertiary UK hospital over a 10-year period. Methods Between April 2011 and March 2021, 45 patients with a median age of 67 years (31–92) who had an esophageal leak were treated with EVT. All patients were treated with an ad-hoc endoluminal vacuum device (EVD) constructed using V.A.C GRANUFOAMTM (KCI) and a standard nasogastric (Ryles) tube. The median Apache II score for patients at the time of leak diagnosis was 20 (6–36). The cause of the leak was anastomotic in 16 patients (36%), iatrogenic in 14 patients (31%), spontaneous in 14 patients (31%), and traumatic in 1 patient (2%). Information related to treatment and outcome was recorded prospectively. Results Successful resolution of the leak was achieved in 39 (87%) patients. The median number of EVD changes required to heal the leak was 6 (1–17). There were no complications related to insertion of the EVD. The median length of hospital stay was 49 days (1–108). Six (13%) patients died during treatment. Six (13%) patients had complications during treatment requiring further intervention; 2 (4%) had a significant bleed requiring angiography and aortic stent placement, 1 (2%) had a stroke, 1 (2%) had a pulmonary embolism, 1 (2%) had a myocardial infarction, and 1 (2%) contracted COVID-19. Conclusion EVT is a safe and effective treatment that can be used successfully to treat esophageal leaks from a disparate range of leak causes in selected critically unwell patients. Further studies are required to develop a standardized procedure and management pathway which will enable broader adoption of EVT in this group of patients.

Use of Li-ESWT, Tadalafil, and a Vacuum Device to Preserve Erectile Function in Subjects Affected by Peyronie’s Disease and Undergoing Grafting Surgery

Background: Peyronie’s disease (PD) is a little-known disease characterized by pain during erections, the presence of penile curvature, and consequent psychological disorders. In addition, concomitant erectile dysfunction may be present. The treatment of PD is adapted to the patient, especially when the penile curvature is >60°; with stabilized pathology, it is preferable to perform penile straightening approaches, such as penile plication and plaque incision, or partial excision and grafting. The most frequent side effect of straightening approaches is the onset of erectile dysfunction due to the formation of venous leakage appearing after the excision of calcific plaque. Materials and methods: All enrolled patients had PD, a curvature >60°, had an IIEF subdomain erectile function score >16, and refused penile prosthesis implantation concurrent with tunica albuginea grafting surgery. Subsequently, 4 weeks after surgery, all patients underwent a rehabilitation protocol that consisted of low-intensity extracorporeal shock wave therapy (Li-ESWT), the administration of 5 mg/daily of tadalafil, and the use of a vacuum device. Results: From January 2014 to March 2016, 15 subjects affected by PD with severe penile curvatures were enrolled in the study. At 6 months after surgery, the IIEF scores for erectile function were not statistically significantly different before and after surgery (p > 0.05); the other items, especially orgasmic function (p = 0.01), sexual desire (p < 0.01), intercourse satisfaction (p = 0.01), and overall satisfaction (p = 0.04), were all statistically significant. The modified EDITS questionnaire reported that 80% of patients were satisfied, that 13.3% were dissatisfied, and that 1 patient (6.6%) was dissatisfied with the surgery. Moreover, there was no statistically significant decrease in the patients’ penile lengths. The aim of this study was to use a rehabilitation protocol consisting of Li-ESWT, the administration of 5 mg/daily, and the use of a vacuum device in order to preserve the erectile function of patients undergoing straightening approaches using surgical grafting. In addition, patient satisfaction following surgery was analyzed.

Maternal and Neonatal Outcomes of Operative Vaginal Deliveries at a Single Tertiary Center

Objectives: Our study sought to assess the maternal and neonatal outcomes of operative vaginal deliveries (OVDs) at Sultan Qaboos University Hospital (SQUH). We assessed the proportion of OVDs along with the proportion of maternal and neonatal outcomes of kiwi OmniCup vacuum, metal cup vacuum, and forceps deliveries. Methods: We conducted a retrospective cohort study in the Obstetrics and Gynecology Department at SQUH from June 2015 to March 2018. The hospital information system was utilized to obtain records of all women who delivered at SQUH by vacuum or forceps during the study period. We collected data on maternal demographics, maternal and neonatal outcomes, and total number of deliveries. Results: During the study period, 3.8% of deliveries were OVDs. The most common instrument used was the Kiwi OmniCup vacuum device. No significant difference was found between the type of tears and instrument used except perineal tears (p =0.003), which was seen more in the vacuum group, particularly Kiwi OmniCup. Neonatal birth weight (p =0.046) was significantly higher in the metallic vacuum cup group. Thirty-one neonates (6.6%) were admitted to the neonatal intensive care unit, and most were born using Kiwi OmniCup vacuum (67.7%). Conclusions: OVD is an ideal alternative to cesarean section with fewer maternal and neonatal complications in women who cannot deliver spontaneously if performed by a well-trained obstetrician.

Desorption from Hot Scandate Cathodes: Effects on Vacuum Device Interior Surfaces after Long-Term Operation

Scandate cathodes have exhibited superior emission properties compared to current state-of-the-art “M-type” thermionic cathodes. However, their integration into vacuum devices is limited in part by a lack of knowledge regarding their functional lifespan and behavior during operation. Here, we consider thermal desorption from scandate cathodes by examining the distribution of material deposited on interior surfaces of a sealed vacuum device after ~26,000 h of cathode operation. XPS, EDS, and TEM analyses indicate that on the order of 1 wt.% of the initial impregnate is desorbed during a cathode’s lifetime, Ca does not desorb uniformly with time, and little to no Sc desorbs from the cathode surfaces (or does so at an undetectable rate). Findings from this first-ever study of a scandate cathode after extremely long-time operation yield insight into the utility of scandate cathodes as components in vacuum devices and suggest possible effects on device performance due to deposition of desorption products on interior device surfaces.