Final implementation, commissioning, and performance of embedded collimator beam position monitors in the Large Hadron Collider

During Long Shutdown 1, 18 Large Hadron Collider (LHC) collimators were replaced with a new design, in which beam position monitor (BPM) pick-up buttons are embedded in the collimator jaws. The BPMs provide a direct measurement of the beam orbit at the collimators, and therefore can be used to align the collimators more quickly than using the standard technique which relies on feedback from beam losses. Online orbit measurements also allow for reducing operational margins in the collimation hierarchy placed specifically to cater for unknown orbit drifts, therefore decreasing the β and increasing the luminosity reach of the LHC. In this paper, the results from the commissioning of the embedded BPMs in the LHC are presented. The data acquisition and control software architectures are reviewed. A comparison with the standard alignment technique is provided, together with a fill-to-fill analysis of the measured orbit in different machine modes, which will also be used to determine suitable beam interlocks for a tighter collimation hierarchy.peer-reviewe

Impact on Patient Care of a Multidisciplinary Center Specializing in Colorectal and Pelvic Reconstruction

Aim of the study: Many patients with an anorectal malformation (ARM) or pelvic anomaly have associated urologic or gynecologic problems. We hypothesized that our multidisciplinary center, which integrates pediatric colorectal, urologic, gynecologic and GI motility services, could impact a patient's anesthetic exposures and hospital visits.Methods: We tabulated during 2015 anesthetic/surgical events, endotracheal intubations, and clinic/hospital visits for all patients having a combined procedure.Main results: Eighty two patients underwent 132 combined procedures (Table 1). The median age at intervention was 3 years [0.2-17], and length of follow up was 25 months [7-31]. The number of procedures in patients who underwent combined surgery was lower as compared to if they had been done independently [1(1-5) vs. 3(2-7) (p < 0.001)]. Intubations were also lower [1[1-3] vs. 2[1-6]; p < 0.001]. Hospital length of stay was significantly lower for the combined procedures vs. the theoretical individual procedures [8 days [3-20] vs. 10 days [4-16]] p < 0.05. Post-operative clinic visits were fewer when combined visits were coordinated as compared to the theoretical individual clinic visits (urology, gynecology, and colorectal) [1[1-4] vs. 2[1-6]; p = < 0.001].Conclusions: Patients with anorectal and pelvic malformations are likely to have many medical or surgical interventions during their lifetime. A multidisciplinary approach can reduce surgical interventions, anesthetic procedures, endotracheal intubations, and hospital/outpatient visits

Pilonidal Disease Mimicking Fistula-in-Ano in a 15-Year-Old Female

Pilonidal disease typically presents with an abscess or intermittent pain and drainage in the sacrococcygeal region during the pubertal years. Further examination typically reveals pits in the midline of the sacrococcyx area due to entrapment of hair with recurrent entrapment, infection, and drainage. The following paper describes an unusual presentation of a pilonidal cyst with fissure and perianal drainage

Surgical Management of Functional Constipation: Preliminary Report of a New Approach Using a Laparoscopic Sigmoid Resection Combined with a Malone Appendicostomy

© 2017 Georg Thieme Verlag KG Stuttgart.New York. Introduction Functional constipation is a common problem in children. It usually can be managed with laxatives but a small subset of patients develop intolerable cramps and need to be temporarily treated with enemas. The senior author has previously reported: 1) open sigmoid resection as a surgical option, but this did not sufficiently reduce the laxative need, then 2) a transanal approach (with resection of rectosigmoid), but this led to a high rate of soiling due to extensive stretching of the anal canal and loss of the rectal reservoir. The understanding of these procedures\u27 results has led us to use a laparoscopic sigmoid ± left colonic resection with a Malone appendicostomy for these patients, to decrease the laxative requirements, temporarily treat with antegrade flushes, and to reduce postoperative soiling. Methods A single-institution retrospective review (3/2014-9/2015) included patients who failed our laxative protocol, and therefore were considered surgical candidates. Patients with anorectal malformation (ARM), Hirschsprung disease, spina bifida, tethered cord, trisomy 21, cerebral palsy, mitochondrial disease, prior colon resection at other facilities, or those that did not participate in our laxative program were excluded. Demographics, duration of symptoms, prior treatments, postoperative complications, and postoperative bowel regimens were evaluated. Results A total of 6 patients (3 males; median age of 12.5 years) presented with soiling related to constipation and intolerance to laxatives. Four patients failed preoperative cecostomy (done prior to referral to us). An average of 4.7 medication treatments were previously tried. In all, 4 patients had required in-patient disimpactions. Duration of symptoms was 7.5 years (median). The median senna dose was 30 mg (range, 15-150 mg), and all patients had intolerable symptoms or failed to empty their colon, which we considered a failed laxative trial. All had contrast enemas that demonstrated a dilated and/or redundant sigmoid colon, and colonic manometry was abnormal in 4. All patients underwent laparoscopic sigmoid and left colon resection, or only sigmoid resection (a low anterior resection). Two patients had postoperative colitis treated with oral antibiotics. The median follow-up was 52 days (range, 8-304 days). Five patients are on antegrade enemas with plans to convert to laxatives at 6 months, 1 is taking laxatives alone at a 33% lower dosage. Five of six are completely clean, 1 soils occasionally and their daily flush is being adjusted. Conclusion Only a minority of patients with functional constipation are medically unmanageable. This preliminary report shows that laparoscopic colon resection combined with antegrade flushes is an effective surgical technique to treat that group. A laparoscopic approach, guided by contrast enema and colonic manometry, allows for a defined resection of the abnormal segment of colon with the advantages of minimally invasive surgery including allowing for an extensive rectal resection (an improvement over open sigmoid resection) and avoidance of overstretching of the anal canal and removal of the rectal reservoir (an improvement over the transanal approach). Having antegrade access is useful to manage soiling and avoiding cramping from laxatives in the early postoperative period. Although our series is small, we believe that long-term most patients can avoid antegrade flushes and be on no, or a dramatically reduced, laxative dose

Use of a Heineke-Mikulicz like stricturoplasty for intractable skin level anal strictures following anoplasty in children with anorectal malformations

© 2016 Elsevier Inc. Introduction We introduced a modification of the Heineke-Mikulicz technique to treat intractable skin level anal strictures post posterior sagittal anorectoplasty (PSARP). The aim of this article is to describe the technique and outcome in a series of patients. Methods This was a retrospective evaluation of patients who had Heineke-Mikulicz like stricturoplasty performed for a post PSARP skin level stricture over a one-year period. Results Five patients who were operated using the technique were reviewed. All had severe anal strictures that could admit Hegar dilator sizes 6 to 9 at 16 months to 5 years after PSARP. All underwent routine dilatations, which became increasingly painful. As an alternative to continued dilatations, an operative procedure was offered. The surgery was done as a day case and lasted 10 to 30 min. The anus at the end of the procedure could comfortably accept a Hegar dilator size 14 to 17. None of the patients had a colostomy after the procedure and there were no complications. Conclusions The Heineke-Mikulicz like stricturoplasty is a simple surgical procedure that can be done in an ambulatory setting to treat children with intractable skin level anal stricture if this develops following definitive surgery for anorectal malformations

Patient and parental scar assessment after single incision versus standard 3-port laparoscopic appendectomy: Long-term follow-up from a prospective randomized trial

Background: Single site laparoscopy for appendectomy is a technique with several case series suggesting a cosmetic advantage, but without prospective comparative data. We conducted a prospective, randomized trial comparing single site laparoscopic appendectomy to the standard 3-port approach, including scar assessment at early and long-term follow-up. Methods: Enrolled patients over 12 years old and parents of patients less than 12 years old were asked to complete the validated Patient Scar Assessment Questionnaire (PSAQ) at early follow-up around 6 weeks and by phone after 18 months. The PSAQ consists of 4 scored subscales: Appearance, Consciousness, Appearance Satisfaction, and Symptom Satisfaction. Each subscale has a set of questions with a 4-point categorical response (1 = most favorable, 4 = least favorable). The sum of the scores quantifies each subscale. Results: Early questionnaires were obtained from 98 3-port and 100 single-site patients with the single-site approach producing superior overall scar assessment (P = 0.003). By telephone follow-up, questionnaires were completed by 49 3-port and 56 single-site patients at a median of 25 (18-32) months. In this longerterm follow-up, overall scar assessment was not significantly different between groups (P = 0.06). Conclusion: Patients or parents express superior scar assessment with the single site approach at early followup, but this difference disappears in the long-term. © 2014 Elsevier Inc. All rights reserved. Laparoscopic appendectomy has dramatically increased over the past 12 years as the operative method of choice for appendiciti

Redo posterior sagittal anorectoplasty for lateral mislocation in patients with anorectal malformations

© 2020 Elsevier Inc. Background: Children undergoing repair of an anorectal malformation (ARM) may have persistent soiling and/or constipation postoperatively. An anatomic reason should be sought; one of the causes for these problems that may require reoperation is mislocation of the rectum and anus outside of the muscle complex. Methods: We reviewed our population of children who underwent re-do anorectoplasty surgery between 2014 and 2019. Indications for surgery and outcomes were recorded. Results: Twelve patients had a lateral mislocation and underwent reoperation. There were no immediate complications in this subgroup. 9 of 10 patients are clean, and 4 are now able to have voluntary bowel movements. Conclusion: For patients who are found to have a significant lateral mislocation, we describe a new surgical technique that replaces the rectum and neo-anus directly in the midline through the muscle complex which may improve functional outcome

First Operational Experience with Embedded Collimator BPMs in the LHC

During Long Shutdown 1, 18 Large Hadron Collider (LHC) collimators were replaced with a new design, in which beam position monitor (BPM) pick-up buttons are embedded in the collimator jaws. The BPMs provide a direct measurement of the beam orbit at the collimators, and therefore can be used to align the collimators more quickly than using the standard technique which relies on feedback from beam losses. Online orbit measurements also mean that margins in the collimation hierarchy placed specifically to cater for unknown orbit drifts can be reduced, therefore increasing the beta-star and luminosity reach of the LHC. In this paper, the first operational results are presented, including a comparison with the standard alignment technique and a fill-to-fill analysis of the measured orbit in different machine modes in the first year of running after the shutdown

Assessing the benefit of reoperations in patients who suffer from fecal incontinence after repair of their anorectal malformation

© 2020 Elsevier Inc. Background and Aim: Patients with a previously repaired anorectal malformation (ARM) can suffer from complications which lead to incontinence. Reoperation can improve the anatomic result, but its impact on functional outcomes is unclear. Methods: We performed a retrospective cohort study of patients with a previously repaired ARM who underwent redo PSARP at our Center and compared results at initial assessment and 12 months after redo. Results: One hundred fifty-three patients underwent a redo PSARP for anoplasty mislocation (n = 93, 61%), stricture (n = 55, 36%), remnant of the original fistula (n = 28, 18%), or rectal prolapse (n = 11, 7%). Post-redo complications included stricture (n = 33, 22%) and dehiscence (n = 5, 3%). At 1-year post-redo, 75/153 (49%) are on laxatives only, of whom 57 (76%) are continent of stool. Of the remaining 78 (51%) patients, 61 (78%) are clean (≤ 1 accident per week) on enemas. Interestingly, 16/79 (20%) of patients with expected poor continence potential were continent of stool on laxatives. Overall, 118/153 (77%) are clean after their redo. Quality of life (76.7 vs. 83.8, p = 0.05) and Baylor continence (29.2 vs. 17.7, p =\u3c0.0001) scores improved. Conclusion: Patients with fecal incontinence after an ARM repair can, with a reoperation, have their anatomy corrected which can restore continence for many, and improve their quality of life. Level of Evidence: IV. Type of study: Retrospective cohort study