Robotic resection of presacral tumors.

BACKGROUND: Presacral tumors are a rare entity typically treated with an open surgical approach. A limited number of minimally invasive resections have been described. The aim of the study is to evaluate the safety and efficacy of roboticresection of presacral tumors. METHODS: This is a retrospective single system analysis, conducted at a quaternary referral academic healthcare system, and included all patients who underwent a robotic excision of a presacral tumor between 2015 and 2023. Outcomes of interest were operative time, estimated blood loss, complications, length of stay, margin status, and recurrence rates. RESULTS: Sixteen patients (11 females and 5 males) were included. The median age of the cohort was 51 years (range 25-69 years). The median operative time was 197 min (range 98-802 min). The median estimated blood loss was 40 ml, ranging from 0 to 1800 ml, with one patient experiencing conversion to open surgery after uncontrolled hemorrhage. Urinary retention was the only postoperative complication that occurred in three patients (19%) and was solved within 30 days in all cases. The median length of stay was one day (range 1-6 days). The median follow-up was 6.7 months (range 1-110 months). All tumors were excised with appropriate margins, but one benign and one malignant tumor recurred (12.5%). Ten tumors were classified as congenital (one was malignant), two were mesenchymal (both malignant), and five were miscellaneous (one malignant). CONCLUSIONS: Robotic resection of select presacral pathology is feasible and safe. Further studies must be conducted to determine complication rates, outcomes, and long-term safety profiles.

Axion Dark Matter Experiment: Detailed design and operations.

Axion dark matter experiment ultra-low noise haloscope technology has enabled the successful completion of two science runs (1A and 1B) that looked for dark matter axions in the 2.66-3.1 µeV mass range with Dine-Fischler-Srednicki-Zhitnisky sensitivity [Du et al., Phys. Rev. Lett. 120, 151301 (2018) and Braine et al., Phys. Rev. Lett. 124, 101303 (2020)]. Therefore, it is the most sensitive axion search experiment to date in this mass range. We discuss the technological advances made in the last several years to achieve this sensitivity, which includes the implementation of components, such as the state-of-the-art quantum-noise-limited amplifiers and a dilution refrigerator. Furthermore, we demonstrate the use of a frequency tunable microstrip superconducting quantum interference device amplifier in run 1A, and a Josephson parametric amplifier in run 1B, along with novel analysis tools that characterize the system noise temperature.

Single-port robotic transanal minimally invasive surgery (SPR-TAMIS) approach to local excision of rectal tumors.

BACKGROUND: Trans-anal excision is the surgical treatment of choice for endoscopically unresectable rectal polyps, early rectal cancers, small carcinoid tumors, and other low-risk tumors. The single-port robotic (SPR) platform is the newest development in robotic surgery capable of performing trans-anal minimally invasive surgery (TAMIS). In theory, the single incision design would naturally lend itself to the size limitation of the anal canal, but in practice, this method has not been tested. Herein we describe the techniques and first reports of performing TAMIS using the SPR platform. TECHNIQUE: We describe in detail how to perform the SPR-TAMIS technique using lessons and experience gained from performing this on five patients who had endoscopically unresectable rectal polyps or T1 rectal cancers. Each patient was followed for a minimum of 30 days and was seen in clinic post-operatively. A retrospective chart review was performed to obtain information on technical success, anatomic measurements, and reported complications. RESULTS: The SPR TAMIS was successfully performed on all five patients without any reported complications. All underwent a non-piecemeal excision and had return of regular bowel function at 30-day follow-up. All patients were discharged from the hospital the same day as their operation. CONCLUSIONS: SPR-TAMIS is a novel, safe, and feasible procedure capable of achieving non-piecemeal resections of low-risk rectal tumors. Further study needs to be conducted to determine complication rates, functional and oncologic outcomes, and ensure the long-term safety profile.

Extended Search for the Invisible Axion with the Axion Dark Matter Experiment.

This Letter reports on a cavity haloscope search for dark matter axions in the Galactic halo in the mass range 2.81-3.31 µeV. This search utilizes the combination of a low-noise Josephson parametric amplifier and a large-cavity haloscope to achieve unprecedented sensitivity across this mass range. This search excludes the full range of axion-photon coupling values predicted in benchmark models of the invisible axion that solve the strong CP problem of quantum chromodynamics.

Risk factors for conversion in laparoscopic and robotic rectal cancer surgery.

BACKGROUND: The aim of this study was to review risk factors for conversion in a cohort of patients with rectal cancer undergoing minimally invasive abdominal surgery. METHODS: A retrospective analysis was performed of consecutive patients operated on from February 2005 to April 2018. Adult patients undergoing low anterior resection or abdominoperineal resection for primary rectal adenocarcinoma by a minimally invasive approach were included. Exclusion criteria were lack of research authorization, stage IV or recurrent rectal cancer, and emergency surgery. Risk factors for conversion were investigated using logistic regression. A subgroup analysis of obese patients (BMI 30 kg/m2 or more) was performed. RESULTS: A total of 600 patients were included in the analysis. The overall conversion rate was 9·2 per cent. Multivariable analysis showed a 72 per cent lower risk of conversion when patients had robotic surgery (odds ratio (OR) 0·28, 95 per cent c.i. 0·15 to 0·52). Obese patients experienced a threefold higher risk of conversion compared with non-obese patients (47 versus 24·4 per cent respectively; P < 0·001). Robotic surgery was associated with a reduced risk of conversion in obese patients (OR 0·22, 0·07 to 0·71). CONCLUSION: Robotic surgery was associated with a lower risk of conversion in patients undergoing minimally invasive rectal cancer surgery, in both obese and non-obese patients.

ANTECEDENTES: El objetivo del estudio era revisar los factores de riesgo para la conversión en una cohorte de pacientes con cáncer de recto sometidos a cirugía abdominal mínimamente invasiva. MÉTODOS: Se realizó un análisis retrospectivo de pacientes consecutivos operados desde febrero de 2005 hasta abril de 2018. Se incluyeron pacientes adultos sometidos a resección anterior baja o resección abdominoperineal por adenocarcinoma primario de recto mediante abordaje mínimamente invasivo. Los criterios de exclusión fueron falta del consentimiento informado, cáncer de recto en estadio IV o recidivado y cirugía urgente. Los factores de riesgo para la conversión se determinaron mediante regresión logística. Se realizó un análisis de subgrupo en pacientes obesos (índice de masa corporal, IMC ≥ 30 kg/m2 ). RESULTADOS: Se incluyeron en el análisis un total de 600 pacientes. La tasa global de conversión fue del 9,2%. El modelo multivariado mostró un riesgo 72% menor de conversión cuando los pacientes fueron tratados mediante cirugía robótica (razón de oportunidades, odds ratio, OR 0,28, i.c. del 95% 0,15-0,52). Los pacientes obesos presentaron un riesgo de conversión tres veces mayor en comparación con los pacientes no obesos (47,3% versus 24,5%, P < 0,001). La cirugía robótica se asoció con una menor probabilidad de conversión en los pacientes obesos (OR 0,22; i.c. del 95% 0,07-0,71). CONCLUSIÓN: La cirugía robótica se asoció con un menor riesgo de conversión en pacientes sometidos a cirugía mínimamente invasiva de cáncer de recto, tanto en pacientes obesos como no obesos.

Identification of patients eligible for discharge within 48 h of colorectal resection.

BACKGROUND: This study aimed to identify patients eligible for a 48-h stay after colorectal resection, to provide guidance for early discharge planning. METHODS: A bi-institutional retrospective cohort study was undertaken of consecutive patients undergoing major elective colorectal resection for benign or malignant pathology within a comprehensive enhanced recovery pathway between 2011 and 2017. Overall and severe (Clavien-Dindo grade IIIb or above) postoperative complication and readmission rates were compared between patients who were discharged within 48 h and those who had hospital stay of 48 h or more. Multinominal logistic regression analysis was performed to ascertain significant factors associated with a short hospital stay (less than 48 h). RESULTS: In total, 686 of 5122 patients (13·4 per cent) were discharged within 48 h. Independent factors favouring a short hospital stay were age below 60 years (odds ratio (OR) 1·34; P = 0·002), ASA grade less than III (OR 1·42; P = 0·003), restrictive fluid management (less than 3000 ml on day of surgery: OR 1·46; P < 0·001), duration of surgery less than 180 min (OR 1·89; P < 0·001), minimally invasive approach (OR 1·92; P < 0·001) and wound contamination grade below III (OR 4·50; P < 0·001), whereas cancer diagnosis (OR 0·55; P < 0·001) and malnutrition (BMI below 18 kg/m2 : OR 0·42; P = 0·008) decreased the likelihood of early discharge. Patients with a 48-h stay had fewer overall (10·8 per cent versus 30·6 per cent in those with a longer stay; P < 0·001) and fewer severe (2·6 versus 10·2 per cent respectively; P < 0·001) complications, and a lower readmission rate (9·0 versus 11·8 per cent; P = 0·035). CONCLUSION: Early discharge of selected patients is safe and does not increase postoperative morbidity or readmission rates. In these patients, outpatient colorectal surgery should be feasible on a large scale with logistical optimization.

ANTECEDENTES: Este estudio tuvo como objetivo identificar pacientes candidatos para una estancia hospitalaria de 48 horas tras resecciones colónicas, con el fin de proporcionar una guía de planificación del alta precoz. MÉTODOS: Estudio de cohortes retrospectivo de pacientes consecutivos sometidos a resección colorrectal electiva mayor por patología benigna o maligna en el marco de un programa integral de recuperación intensificada (enhanced recovery pathway, ERP), de dos hospitales entre 2011 y 2017. Se compararon las tasas de complicaciones postoperatorias globales y graves (Clavien ≥ IIIb) y de reingresos entre dos grupos (< 48 horas versus ≥ 48 horas de estancia hospitalaria). Se llevó a cabo una regresión logística multinominal de factores significativos (P < 0,05) asociados con una estancia corta (< 48 horas). RESULTADOS: En total, 686/5.122 pacientes (13,4%) fueron dados de alta dentro de las primeras 48 horas. Los factores independientes que propiciaron una estancia corta fueron la edad < 60 años (razón de oportunidades, odds ratio, OR 1,34, P = 0,002), puntuación < 3 de la American Society of Anesthesiologists (ASA) (OR 1,42, P = 0,003), manejo restrictivo del aporte de líquidos (< 3000 mL en el día de la cirugía: OR 1,46, P < 0,001), duración de la cirugía < 180 minutos (OR 1,89, P < 0,001), abordaje mínimamente invasivo (OR 1,92, P < 0,001) and tipo de herida clase < 3 (OR 4,5, P < 0,001), mientras que el diagnóstico de cáncer (OR 0,55, P < 0,001) y la malnutrición (IMC < 18 kg/m2 : OR 0,42, P = 0,008) disminuyeron la probabilidad de alta precoz. Los pacientes con una estancia de 48 horas tuvieron menos complicaciones globales (10,8% versus 30,6%, P < 0,001), menos complicaciones graves (2,6% versus 10,2%, P < 0,001) y una menor tasa de reingresos (9% versus 11,8%, P = 0,035). CONCLUSIÓN: El alta precoz en pacientes seleccionados es segura y no aumenta las tasas de morbilidad postoperatoria o de reingresos. En estos pacientes, la cirugía colorrectal ambulatoria debería ser viable a gran escala con una optimización de la logística.

A 25 year experience of perineal hernia repair.

PURPOSE: Though perineal hernias remain rare, the incidence is reportedly rising. Secondary to the historical rarity, optimal method of repair and outcomes after repair remain poorly understood. Therefore, we reviewed the past 25 years of our institutional experience with perineal hernia repair. METHODS: A retrospective review of an institution-maintained database was conducted from January 1, 1994 to January 31, 2018 for patients undergoing perineal hernia repair. Data were collected on patient characteristics, operative technique, and post-operative outcomes. RESULTS: Twenty-one patients (n = 12 male) underwent perineal hernia repair in the study period with two-thirds of the operations occurring in the most recent 7 years (since January 1, 2011). The median time to repair was 13 months (range 2-127) after index operation. The approach was transabdominal in nine, perineal in nine, and combined in three. Mesh, a tissue flap, or a combination of these was used in 19 of the cases and 6 additional abdominal wall hernias were repaired concurrently. Post-operative complications consisted of superficial surgical-site infection (n = 2), infected seroma (n = 1), and a missed enterotomy (n = 1). Follow-up ranged from 0 to 112 months (median 2 months) and only one recurrence was noted. CONCLUSION: Presentation for repair of perineal hernia has increased at our instituion over the past 2 decades. Outcomes did not differ between the three repair approaches and the choice of mesh or tissue-based repair. Surgeons should base these decisions on hernia complexity and local tissue conditions.

Short-term postoperative outcomes following robotic versus laparoscopic ileal pouch-anal anastomosis are equivalent.

BACKGROUND: Minimally invasive approaches have become the standard of care for ileal pouch-anal anastomoses (IPAA). There are few reports comparing outcomes following a laparoscopic versus robotic approach. Our aim was to determine if there were any differences in the 30-day postoperative outcomes following IPAA performed laparoscopically versus robotically. METHODS: A retrospective chart review of all laparoscopic and robotic IPAA performed between January 1, 2015 and June 30, 2018 was carried out. Patients included were adult patients who underwent a proctectomy and IPAA utilizing either a laparoscopic or robotic approach. Data collected included patient demographics, operative variables, and 30-day postoperative outcomes. RESULTS: A total of 132 patients had a minimally invasive IPAA; 58 were performed laparoscopically and 74 robotically. Less than half the patients were female (n = 55; 41.7%) with a median age of 37 years (range 18-68 years). The majority of patients had a diagnosis of ulcerative colitis (n = 103; 78.0%) with medically refractory disease (n = 87; 65.9%). A greater proportion of patients in the laparoscopic cohort had a prolonged length of stay (n = 27; 46.6% versus n = 18; 24.3%; p < 0.001) and a two-stage approach (n = 56; 96.6% versus n = 37; 50%; p < 0.001), but there were no differences in the rates between the laparoscopic versus robotic cohorts of superficial surgical site infection (6.9% versus 6.8%; p = 0.99), peripouch abscess (15.5% versus 6.8%; p = 0.11), anastomotic leak (6.9% versus 2.7%; p = 0.21), pelvic abscess (15.5% versus 6.8%; p = 0.11), and pelvic sepsis (15.5% versus 6.8%; p = 0.11), readmission (24.1% versus 17.6%; p = 0.35) or reoperation (6.9% versus 5.4%; p = 0.72). On multivariable analysis, only male sex remained predictive of prolonged length of stay, and a robotic approach trended toward a decreased rate of prolonged length of stay. CONCLUSIONS: Laparoscopic and robotic IPAA have equivalent postoperative morbidity underscoring the safety of the continued expansion of the robotic platform for pouch surgery.

Randomized clinical trial of liposomal bupivacaine transverse abdominis plane block versus intrathecal analgesia in colorectal surgery.

BACKGROUND: Transverse abdominis plane (TAP) block is considered an effective alternative to neuraxial analgesia for abdominal surgery. However, limited evidence supports its use over traditional analgesic modalities in colorectal surgery. This study compared the analgesic efficacy of liposomal bupivacaine TAP block with intrathecal (IT) opioid administration in a multicentre RCT. METHODS: Patients undergoing elective small bowel or colorectal resection were randomized to receive TAP block or a single injection of IT analgesia with hydromorphone. Patients were assessed at 4, 8, 16, 24 and 48 h after surgery. Primary outcomes were mean pain scores and morphine milligram equivalents (MMEs) administered within 48 h after surgery. Secondary outcomes included duration of hospital stay, incidence of postoperative ileus and use of intravenous patient-controlled analgesia. RESULTS: In total, 209 patients were recruited and 200 completed the trial (TAP 102, IT 98). The TAP group had a 1·6-point greater mean pain score than the IT group at 4 h after surgery, and this difference lasted for 16 h after operation. The TAP group received more MMEs within the first 24 h after surgery than the IT group (median difference in MMEs 10·0, 95 per cent c.i. 3·0 to 20·5). There were no differences in MME use at 24 and 48 h, or with respect to secondary outcomes. CONCLUSION: IT opioid administration provided better immediate postoperative pain control than TAP block. Both modalities resulted in low pain scores in patients undergoing elective colorectal surgery and should be considered in multimodal postoperative analgesic plans. Registration number: NCT02356198 ( http://www.clinicaltrials.gov).

Impact of enhanced recovery on oncological outcomes following minimally invasive surgery for rectal cancer.

BACKGROUND: Oncological outcomes of locally advanced rectal cancer depend on the quality of surgical and oncological management. Enhanced recovery pathways (ERPs) have yet to be assessed for their oncological impact when used in combination with minimally invasive surgery. This study assessed outcomes with or without an ERP in patients with rectal cancer. METHODS: This was a retrospective analysis of all consecutive adult patients who underwent elective minimally invasive surgery for primary rectal adenocarcinoma with curative intent between February 2005 and April 2018. Both laparoscopic and robotic procedures were included. Short-term morbidity and overall survival were compared between patients treated according to the institutional ERP and those who received conventional care. RESULTS: A total of 600 patients underwent minimally invasive surgery, of whom 320 (53·3 per cent) were treated according to the ERP and 280 (46·7 per cent) received conventional care. ERP was associated with less overall morbidity (34·7 versus 54·3 per cent; P < 0·001). Patients in the ERP group had improved overall survival on univariable (91·4 versus 81·7 per cent at 5 years; hazard ratio (HR) 0·53, 95 per cent c.i. 0·28 to 0·99) but not multivariable (HR 0·78, 0·41 to 1·50) analysis. Multivariable analysis revealed age (HR 1·46, 1·17 to 1·82), male sex (HR 1·98, 1·05 to 3·70) and complications (HR 2·23, 1·30 to 3·83) as independent risk factors for compromised overall survival. Disease-free survival was comparable for patients who had ERP or conventional treatment (80·5 versus 84·6 per cent at 5 years respectively; P = 0·272). CONCLUSION: Treatment within an ERP was associated with a lower morbidity risk that may have had a subtle impact on overall but not disease-specific survival.

Outcomes of Early Removal of Urinary Catheter Following Rectal Resection for Cancer.

PURPOSE: Early postoperative urinary catheter removal decreases urinary tract infection (UTI) rate and accelerates patient mobilization. The aim of this study is to determine the results of systematic urinary catheter removal on postoperative day (POD) 1 in patients undergoing rectal resection for cancer. PATIENTS AND METHODS: Using a prospectively maintained database of 469 patients who underwent rectal resection for cancer, a retrospective review of all patients with urinary catheter removal on POD1 was conducted. Patients unable to void 6 h after catheter removal underwent in and out urinary catheterization (IOC group) and were compared with patients who voided spontaneously (non-IOC group) to determine risk factors for IOC. RESULTS: A total of 417 patients were identified, including 274 (66%) men. Median age was 59 (50-68) years. Abdominoperineal resection (APR) was performed in 134 (32%), and complex surgery with resection of at least one other organ in 72 (17%) patients. Non-IOC and IOC groups included 245 (59%) and 172 (41%) patients, respectively. Five independent predictive factors for IOC were male gender, obesity, history of obstructive urinary disease, APR, and metastatic disease. The cumulative risk of IOC in patients with zero, one, two, and at least three risk factors was 8%, 31%, 52%, and 68% on POD1, and 2%, 12%, 23%, and 30% on POD5, respectively (p < 0.001). Thirteen patients (3%) developed UTI. CONCLUSIONS: Early removal of urinary catheter resulted in 59% of patients voiding spontaneously with no need for IOC following rectal resection. Patients without any predictive factors had less than 10% risk of urinary dysfunction.

Does obesity impact postoperative outcomes following robotic-assisted surgery for rectal cancer?

INTRODUCTION: Obesity has been identified as a risk factor for both conversion and severe postoperative morbidity in patients undergoing laparoscopic rectal resection. Robotic-assisted surgery (RAS) is proposed to overcome some of the technical limitations associated with laparoscopic surgery for rectal cancer. The aim of our study was to determine if obesity remains a risk factor for severe morbidity in patients undergoing robotic-assisted rectal resection. PATIENTS: This study was a retrospective review of a prospective database. A total of 183 patients undergoing restorative RAS for rectal cancer between 2007 and 2016 were divided into 2 groups: control (BMI < 30 kg/m2; n = 125) and obese (BMI ≥ 30 kg/m2; n = 58). Clinicopathologic data, 30-day postoperative morbidity, and perioperative outcomes were compared between groups. The main outcome was severe postoperative morbidity defined as any complication graded Clavien-Dindo ≥ 3. RESULTS: Control and obese groups had similar clinicopathologic characteristics. Severe complications were observed in 9 (7%) and 4 (7%) patients, respectively (p > 0.99). Obesity did not impact conversion, anastomotic leak rate, length of stay, or readmission but was significantly associated with increased postoperative morbidity (29 vs. 45%; p = 0.04) and especially more postoperative ileus (11 vs. 26%; p = 0.01). Obesity and male gender were the two independent risk factors for postoperative overall morbidity (OR 1.97; 95% CI 1.02-3.94; p = 0.04 and OR 2.23; 95% CI 1.10-4.76; p = 0.03, respectively). CONCLUSION: Obesity did not impact severe morbidity or conversion rate following RAS for rectal cancer but remained a risk factor for overall morbidity and especially postoperative ileus.

Search for Invisible Axion Dark Matter with the Axion Dark Matter Experiment.

This Letter reports the results from a haloscope search for dark matter axions with masses between 2.66 and 2.81 µeV. The search excludes the range of axion-photon couplings predicted by plausible models of the invisible axion. This unprecedented sensitivity is achieved by operating a large-volume haloscope at subkelvin temperatures, thereby reducing thermal noise as well as the excess noise from the ultralow-noise superconducting quantum interference device amplifier used for the signal power readout. Ongoing searches will provide nearly definitive tests of the invisible axion model over a wide range of axion masses.

A systematic review of minimally invasive surgery for retrorectal tumors.

Retrorectal tumors are rare tumors that require resection for symptoms, malignancy and potential malignant transformation. Traditional approaches have included laparotomy, perineal excision or a combination. Multiple minimally invasive techniques are available which have the potential to minimize morbidity and enhance recovery. We performed a systematic review of the literature to determine the feasibility and surgical outcomes of retrorectal tumors approached using minimally invasive surgical techniques. Publications in which adult patients (≥ 18 years) had a minimally invasive approach (laparoscopic or robotic) for resection of a primary retrorectal tumor were included. Data were collected on approach, preoperative investigation, size and sacral level of the tumor, operating time, length of stay, perioperative complications, margins and recurrence. Thirty-five articles which included a total of 82 patients met the inclusion criteria. The majority of patients were female (n = 65; 79.2%), with a mean age of 41.7 years (range 18-89 years). Seventy-three patients (89.0%) underwent laparoscopic or combined laparoscopic-perineal resection, and 9 (10.8%) had a robotic approach. The conversion rate was 5.5%. The overall 30-day morbidity rate was 15.7%, including 1 intraoperative rectal injury (1.2%). Ninety-five percent (n = 78) of the retrorectal tumors were benign. Median length of stay was 4 days for both laparoscopic and robotic groups, with ranges of 1-8 and 2-10 days, respectively. No tumor recurrence was noted during follow-up [median 28 months (range 5-71 months)]. A minimally invasive approach for the resection of retrorectal tumors is feasible in selected patients. Careful patient selection is necessary to avoid incomplete resection and higher morbidity than traditional approaches.

Prognostic value of pathological node status after neoadjuvant radiotherapy for rectal cancer.

BACKGROUND: The prognostic value of pathological lymph node status following neoadjuvant radiotherapy (ypN) remains unclear. This study was designed to determine whether ypN status predicted overall survival. METHODS: Patients with locally advanced rectal adenocarcinoma who underwent neoadjuvant long-course radiation between 2005 and 2014 were identified from the National Cancer Data Base, and divided into ypN0, ypN1 and ypN2 groups. The primary outcome was overall survival. Univariable and multivariable analyses were used to determine factors associated with overall survival. RESULTS: Of 12 271 patients, 3713 (30·3 per cent) were found to have residual nodal positivity. A majority of patients with ypN1 (1663 of 2562) and ypN2 (878 of 1151) disease had suspected lymph node-positive disease before neoadjuvant therapy, compared with 3959 of 8558 with ypN0 tumours (P < 0·001). Moreover, ypN1 and ypN2 were significantly associated with ypT3-4 disease (65·7 and 83·0 per cent respectively versus 39·4 per cent for ypN0; P < 0·001). In unadjusted analyses, survival differed significantly between ypN groups (P < 0·001). Five-year survival rates were 81·6, 71·3 and 55·0 per cent for patients with ypN0, ypN1 and ypN2 disease respectively. After adjustment for confounding variables, ypN1 and ypN2 remained independently associated with overall survival: hazard ratio (HR) 1·61 (95 per cent c.i. 1·46 to 1·77) and 2·63 (2·34 to 2·95) respectively (P < 0·001). Overall survival was significantly longer in patients with ypN1-2 combined with ypT0-2 status than among those with ypT3-4 tumours even with ypN0 status (P = 0·031). Clinical nodal status before neoadjuvant therapy was not significantly associated with overall survival (HR 1·05, 0·97 to 1·13; P = 0·259). CONCLUSION: Both ypT and ypN status is of prognostic significance following neoadjuvant therapy for rectal cancer.

Does prolonged operative time impact postoperative morbidity in patients undergoing robotic-assisted rectal resection for cancer?

BACKGROUND: Several studies have shown a correlation between longer operative times and higher rates of postoperative morbidity for open and laparoscopic surgery for rectal cancer. The aim of the study was to determine the impact of prolonged operative time on early postoperative morbidity in patients undergoing robotic-assisted rectal cancer resection. METHODS: The study was a retrospective review of a prospectively maintained database conducted in two centers of the same institution. A total of 260 consecutive patients undergoing with robotic-assisted resection for rectal cancer between 2007 and 2016 were included. Patients were divided into two groups regarding median operative time: > 300 min (prolonged operative time; n = 133) and ≤ 300 min (control; n = 127). Patient characteristics, operative and postoperative data were compared between groups. Univariate and multivariate analyses were performed to determine whether prolonged operative time was a predictive factor of 30-day postoperative morbidity. RESULTS: Prolonged operative time was noted more frequently in males (p = 0.02), patients with higher BMI (p < 0.01), more severe comorbidities (p < 0.01), in tumors of the mid-rectum, and in surgery performed after neoadjuvant chemoradiation or upon surgeons' learning curve. The two groups had similar overall postoperative morbidity (32 vs. 41%; p = 0.16) and severe morbidity (6 vs. 6%; p = 0.92) rates. Prolonged operative time was associated with longer hospital stay (3.8 ± 2.5 vs. 5.0 ± 3.7 days; p = 0.004) in univariate analysis. Prolonged operative time was not independently associated with postoperative morbidity or with increased hospital stay on multivariate analysis. CONCLUSION: In our study, prolonged operative time was not associated with an over-risk of morbidity in patients undergoing robotic resection for rectal cancer. These results suggest that more difficult robotic procedures do not lead to increased postoperative morbidity.

Piezoelectrically Tuned Multimode Cavity Search for Axion Dark Matter.

The µeV axion is a well-motivated extension to the standard model. The Axion Dark Matter eXperiment (ADMX) collaboration seeks to discover this particle by looking for the resonant conversion of dark-matter axions to microwave photons in a strong magnetic field. In this Letter, we report results from a pathfinder experiment, the ADMX "Sidecar," which is designed to pave the way for future, higher mass, searches. This testbed experiment lives inside of and operates in tandem with the main ADMX experiment. The Sidecar experiment excludes masses in three widely spaced frequency ranges (4202-4249, 5086-5799, and 7173-7203 MHz). In addition, Sidecar demonstrates the successful use of a piezoelectric actuator for cavity tuning. Finally, this publication is the first to report data measured using both the TM_{010} and TM_{020} modes.

Magnetic flux noise in dc SQUIDs: temperature and geometry dependence.

The spectral density S(Φ)(f) = A(2)/(f/1 Hz)(α) of magnetic flux noise in ten dc superconducting quantum interference devices (SQUIDs) with systematically varied geometries shows that α increases as the temperature is lowered; in so doing, each spectrum pivots about a nearly constant frequency. The mean-square flux noise, inferred by integrating the power spectra, grows rapidly with temperature and at a given temperature is approximately independent of the outer dimension of a given SQUID. These results are incompatible with a model based on the random reversal of independent, surface spins.