Utilizing multiplexing of structured THz beams carrying orbital-angular-momentum for high-capacity communications.

Structured electromagnetic (EM) waves have been explored in various frequency regimes to enhance the capacity of communication systems by multiplexing multiple co-propagating beams with mutually orthogonal spatial modal structures (i.e., mode-division multiplexing). Such structured EM waves include beams carrying orbital angular momentum (OAM). An area of increased recent interest is the use of terahertz (THz) beams for free-space communications, which tends to have: (a) larger bandwidth and lower beam divergence than millimeter-waves, and (b) lower interaction with matter conditions than optical waves. Here, we explore the multiplexing of THz OAM beams for high-capacity communications. Specifically, we experimentally demonstrate communication systems with two multiplexed THz OAM beams at a carrier frequency of 0.3 THz. We achieve a 60-Gbit/s quadrature-phase-shift-keying (QPSK) and a 24-Gbit/s 16 quadrature amplitude modulation (16-QAM) data transmission with bit-error rates below 3.8 × 10-3. In addition, to show the compatibility of different multiplexing approaches (e.g., polarization-, frequency-, and mode-division multiplexing), we demonstrate an 80-Gbit/s QPSK THz communication link by multiplexing 8 data channels at 2 polarizations, 2 frequencies, and 2 OAM modes.

Receiver aperture and multipath effects on power loss and modal crosstalk in a THz wireless link using orbital-angular-momentum multiplexing.

The channel capacity of terahertz (THz) wireless communications can be increased by multiplexing multiple orthogonal data-carrying orbital-angular-momentum (OAM) beams. In THz links using OAM multiplexing (e.g., Laguerre-Gaussian [Formula: see text] beams with p = 0), the system performance might degrade due to limited receiver aperture size and multipath effects. A limited-size aperture can truncate the received beam profile along the radial direction. In addition, due to beam divergence, part of the beam might interact with reflectors in the environment, causing the signal to reflect and interfere at the receiver with the directly propagating part of the beam; this is known as the multipath effect. In this paper, we simulate and analyze the impact of both effects on the equality of the THz OAM link by considering a full two-dimensional (2-D) LG modal set. The simulation results show (i) a limited-size receiver aperture can induce power loss and modal power coupling mainly to LG modes with the same ℓ but p > 0 for directly propagated OAM beams; (ii) the multipath effect can induce modal power coupling across multiple 2-D LG modes, which leads to inter-channel coupling among the different channels in an OAM multiplexed link; (iii) the interference between the reflected and direct beams can induce intra-channel coupling between the received signals from the reflected and direct beams; and (iv) beams with a higher OAM order (e.g., from ± 1 to ± 5) or a lower carrier frequency (e.g., from 0.1 to 1 THz) experience larger intra- and inter-channel coupling. The intra- and inter-channel coupling in an OAM-multiplexed THz link can degrade the signal-to-noise ratio (SNR) and induce SNR penalty when compared to a single-channel system.

Effect of Changing Surgical Instruments Before Wound Closure to Prevent Wound Infection in Lower GI Surgery: A Randomized Controlled Trial.

BACKGROUND: Surgical site infection is a major surgical complication and has been studied extensively. However, the efficacy of changing surgical instruments before wound closure remains unclear. OBJECTIVE: The aim of this study was to investigate the efficacy of changing surgical instruments to prevent incisional surgical site infection during lower GI surgery. DESIGN: This was a randomized controlled trial. SETTINGS: This study was conducted at the Hyogo College of Medicine in Japan. PATIENTS: Patients undergoing elective lower GI surgery with open laparotomy were included. INTERVENTIONS: Patients were randomly assigned to 1 of 2 groups. In group A, the surgeon changed surgical instruments before wound closure, and in group B, the patients underwent conventional closure. MAIN OUTCOME MEASURES: The primary end point was the incidence of incisional surgical site infection. The secondary end point was the incidence of surgical site infection restricted to clean-contaminated surgery. RESULTS: A total of 453 patients were eligible for this trial. The incidence of incisional surgical site infection was not significantly different between group A (18/213; 8.5%) and group B (24/224; 10.7%; p = 0.78). In the clean-contaminated surgery group, the incidence of incisional surgical site infection was 13 (6.8%) of 191 in group A and 9 (4.7%) of 190 in group B (p = 0.51). LIMITATIONS: This was a single-center study. CONCLUSIONS: Changing surgical instruments did not decrease the rate of incisional surgical site infection in patients undergoing lower GI surgery in either all wound classes or clean-contaminated conditions. See Video Abstract at http://links.lww.com/DCR/B701. EFECTO DE REALIZAR CAMBIO DE LOS INSTRUMENTOS QUIRRGICOS ANTES DEL CIERRE DE LA INCISIN EN LA INFECCIN DE LA HERIDA DEL SITIO QUIRRGICO EN CIRUGA DEL TUBO DIGESTIVO BAJO ESTUDIO ALEATORIO CONTROLADO: ANTECEDENTES:La infección del sitio quirúrgico es una complicación importante y se ha estudiado ampliamente. Sin embargo, la eficacia de cambiar los instrumentos quirúrgicos antes del cierre de la herida sigue sin estar clara.OBJETIVO:El objetivo de este estudio es investigar la eficacia de cambiar el instrumental quirúrgico en la prevención de la infección del sitio quirúrgico en cirugía gastrointestinal inferior.DISEÑO:Estudio aleatorio controlado.AJUSTE:Este estudio se realizó en la Facultad de Medicina de Hyogo en Japón.PACIENTES:Se incluyeron pacientes sometidos a cirugía electiva de tubo digestivo bajo con laparotomía abierta.INTERVENCIONES:Los pacientes fueron asignados aleatoriamente a uno de dos grupos. En el grupo A, el cirujano cambió el instrumental quirúrgico antes del cierre de la herida, y en el grupo B, los pacientes se sometieron a un cierre convencional.PRINCIPALES MEDIDAS DE RESULTADO:El criterio de valoración principal fue la incidencia de infección del sitio quirúrgico de la incisión. El criterio de valoración secundario fue la incidencia de infección del sitio quirúrgico restringida a la cirugía limpia contaminada.RESULTADOS:Un total de 453 pacientes fueron elegibles para este ensayo. La incidencia de infección del sitio quirúrgico no fue significativamente diferente entre el grupo A (18/213; 8,5%) y el grupo B (24/224; 10,7%) (p = 0,78). En el grupo de cirugía limpia-contaminada, la incidencia de infección del sitio quirúrgico incisional fue 13/191 (6,8%) en el grupo A y 9/190 (4,7%) en el grupo B (p = 0,51).LIMITACIÓN:Estudio de un solo centro.CONCLUSIÓNES:El cambio de instrumentos quirúrgicos no disminuyó la tasa de infección del sitio quirúrgico en todas las clases de heridas o condiciones limpias-contaminadas. Consulte Video Resumen en http://links.lww.com/DCR/B701.

Modal coupling and crosstalk due to turbulence and divergence on free space THz links using multiple orbital angular momentum beams.

Orbital-angular-momentum (OAM) multiplexing has been utilized to increase the channel capacity in both millimeter-wave and optical domains. Terahertz (THz) wireless communication is attracting increasing attention due to its broadband spectral resources. Thus, it might be valuable to explore the system performance of THz OAM links to further increase the channel capacity. In this paper, we study through simulations the fundamental system-degrading effects when using multiple OAM beams in THz communications links under atmospheric turbulence. We simulate and analyze the effects of divergence, turbulence, limited-size aperture, and misalignment on the signal power and crosstalk of THz OAM links. We find through simulations that the system-degrading effects are different in two scenarios with atmosphere turbulence: (a) when we consider the same strength of phasefront distortion, faster divergence (i.e., lower frequency; smaller beam waist) leads to higher power leakage from the transmitted mode to neighbouring modes; and (b) however, when we consider the same atmospheric turbulence, the divergence effect tends to affect the power leakage much less, and the power leakage increases as the frequency, beam waist, or OAM order increases. Simulation results show that: (i) the crosstalk to the neighbouring mode remains < - 15 dB for a 1-km link under calm weather, when we transmit OAM + 4 at 0.5 THz with a beam waist of 1 m; (ii) for the 3-OAM-multiplexed THz links, the signal-to-interference ratio (SIR) increases by ~ 5-7 dB if the mode spacing increases by 1, and SIR decreases with the multiplexed mode number; and (iii) limited aperture size and misalignment lead to power leakage to other modes under calm weather, while it tends to be unobtrusive under bad weather.

Incidence, Risk Factors and Outcomes of Cancer of the Anal Transitional Zone in Patients with Ulcerative Colitis.

BACKGROUND AND AIMS: Performing a mucosectomy with a hand-sewn ileal pouch-anal anastomosis [IPAA] for ulcerative colitis [UC] theoretically reduces the risk of carcinoma arising from the anal transitional zone [ATZ]. Although current guidelines suggest a stapled anastomosis due to the low incidence of cancer after pouch surgery in UC patients, only a few small series have addressed the oncological advantage of mucosectomy. Therefore, we aimed to investigate the incidence of ATZ/pouch cancer. METHODS: A total of 1970 UC patients who underwent surgery between April 1987 and December 2018 were included. We retrospectively analysed the incidences of primary ATZ cancer in the original operative specimen and de novo ATZ/pouch cancer after surgery. Possible risk factors for primary ATZ cancer and the pouch survival rate were assessed. RESULTS: Fourteen [6.4%] primary ATZ cancers developed in 220 UC-colorectal cancer [CRC] cases. Multiple (odds ratio [OR] = 8.79, 95% confidence interval [CI] 2.77-27.83, p < 0.01) and rectal [OR = 6.48, 95% CI 1.41-29.7, p = 0.01] cancers were identified as independent risk factors for primary ATZ cancer. Four of 1970 [0.2%] patients developed de novo ATZ/pouch cancer and dysplasia. The 10-year estimated cumulative pouch survival rate was not significantly different between stapled IPAA and hand-sewn IPAA cases [95.9% and 97.3%, p = 0.25]. CONCLUSION: The risk of de novo ATZ/pouch cancer and dysplasia was rare. The decision to perform a hand-sewn or a stapled IAA should be made on a case-by-case basis. However, the relatively high incidence of primary ATZ cancer in UC patients with CRC suggests that mucosectomy should be recommended for this patient group.

Functional Outcomes and Quality of Life in Elderly Patients after Restorative Proctocolectomy for Ulcerative Colitis.

BACKGROUND/AIM: Ileal pouch anal anastomosis (IPAA) has become the surgical procedure of choice for patients with ulcerative colitis (UC). However, to date few studies have examined functional outcomes or quality of life (QOL) in elderly patients after pouch construction. METHODS: In December 2017, we sent questionnaires to 224 patients aged 65 years and older at the time who underwent an IPAA at our hospital between June 1987 and May 2015 regarding issues related to QOL and functional outcomes. Responders aged 65-69 years old were defined as the elderly group (EG), while those 70 years old and over comprised the super-EG (SEG). RESULTS: The response rate was 60.7% (136/224); 70 patients were classified as EG, and 66 were classified as SEG. The SEG were older at the time of the IPAA and during the follow-up period (p < 0.01). The stool frequency per day was 8 times in both groups (p = 0.21). There was no significant difference between the EG and SEG with regard to daytime (53 vs. 56%, p = 0.73) or nighttime (65.7 vs. 53%, p = 0.16) soiling. There was also no difference in the exacerbation of daytime or nighttime soiling compared to the first year after the operation (daytime 5.7 vs. 12.1%, p = 0.23; nighttime 7.1 vs. 9.1%, p = 0.76). QOL was evaluated using the modified fecal incontinence QOL (mFIQL) scale, with no significant difference between the EG and SEG (27 vs. 31 points). Since both groups had mFIQL scores <50, QOL was considered to be maintained. CONCLUSION: In our analysis of elderly patients in the long-term period following surgery for UC, some noted fecal soiling, though QOL was largely maintained, and there were no serious effects on daily life.

Associations between multiple immunosuppressive treatments before surgery and surgical morbidity in patients with ulcerative colitis during the era of biologics.

PURPOSE: It is unclear whether immunomodulators or biologics, with the exception of corticosteroids, can be risk factors for postoperative infectious complications of ulcerative colitis (UC). Moreover, many immunosuppressive therapies including some biologics are used mainly to treat UC, and many patients are on multi-agent immunosuppressive therapy at the time of surgery. Therefore, we evaluated the influence of pre-operative multiple immunosuppressive agents on the occurrence of surgical site infection (SSI) in UC during the era of biologics. METHODS: We reviewed surveillance data from 301 patients who underwent surgery between January 2015 and April 2018. The incidences of SSI and possible risk factors among patients receiving different immunosuppressive therapies were compared and analyzed. RESULTS: The incidence of incisional SSI was 6.6%, and that of organ/space SSI was 7.0%. Doses of corticosteroids were significantly decreased because of the recent shift toward the use of biologics. The types and numbers of immunosuppressive agents did not significantly correlate with each incidence. Age ≥ 65 years (odds ratio (OR) 3.0), total prednisolone dose ≥ 9000 mg (OR 2.7), and perioperative blood transfusion (OR 3.6) were shown to be independent risk factors for incisional SSI, whereas duration of surgery ≥ 252 min (OR 3.8), urgent/emergent surgery (OR 2.9), and perioperative blood transfusion (OR 2.6) were identified as independent risk factors for organ/space SSI. CONCLUSIONS: Although no correlation between pre-operative immunosuppressive therapies, except for corticosteroids, was found, selection bias may have occurred due to treatment before surgery. However, biologics, calcineurin inhibitors, and thiopurines did not affect surgical morbidity in UC.

Efficacy of Preoperative Oral Antibiotic Prophylaxis for the Prevention of Surgical Site Infections in Patients With Crohn Disease: A Randomized Controlled Trial.

OBJECTIVES: We investigated the efficacy of oral antimicrobial prophylaxis in patients undergoing surgery for Crohn disease. BACKGROUND: Although oral antibiotic prophylaxis with mechanical bowel preparation has been recommended for colorectal surgery, the use of this approach remains somewhat controversial. Moreover, the efficacy of this approach for inflammatory bowel disease also remains unclear. METHODS: This study was conducted as a randomized controlled trial at the Hyogo College of Medicine. The study protocols were registered with the University Hospital Medical Information Network Clinical Trials Registry (000013369). In this study, 335 patients with Crohn disease who were scheduled to undergo intestinal resection with an open approach were randomly assigned to either group A or group B. The patients in group A received both preoperative oral antibiotics and intravenous antimicrobial prophylaxis, and intravenous antimicrobial prophylaxis alone was given to the patients in group B. All patients underwent preoperative mechanical bowel preparation with sodium picosulfate hydrate. The primary endpoint of this study was the incidence of surgical site infection (SSI) according to an intention-to-treat analysis. RESULTS: Although the incidences of overall and organ/space SSI were not significantly different, the incidence of incisional SSI was significantly lower in group A (12/163; 7.4%) than in group B (27/162; 16.6%) (P = 0.01). In the multivariate analysis, the absence of oral antibiotic prophylaxis was an independent risk factor for incisional SSI (odds ratio: 3.3; 95% confidence interval: 1.3-8.3; P = 0.01). CONCLUSIONS: Combined oral and intravenous antimicrobial prophylaxis in patients with Crohn disease contributed to the prevention of SSI.

The Use of Oral Herbal Medicine (Hange-Shashin-To) in Patients with Pouchitis: A Pilot Study.

OBJECTIVES: Hange-Shashin-To (HST), which is a combination of seven herbs, has previously been used in the treatment of inflammatory or ulcerative gut disease. The aim of this study was to evaluate the safety and efficacy of HST for the treatment of chronic pouchitis. METHODS: Nineteen patients with chronic pouchitis, defined as either frequent episodes (≥ three episodes per six months) of pouchitis or persistent symptoms that required continuous antibiotic therapies, were selected and treated with ciprofloxacin (CPFX) 600 mg/day for 2 weeks (week 0~2) and HST 3,750 mg/day for 32 weeks (week 0~32). The Pouchitis Disease Activity Index (PDAI) score was measured at week 0 and 6 for short-term evaluation. For long-term evaluation, total CPFX dose in the 26-week period prior to study entry (from 30 weeks before study entry to 5 weeks before study entry) was compared with the total CPFX dose during the 26-week study period (week 7~32). Although no concomitant administration of CPFX was permitted from week 2-6, patients whose condition deteriorated were prescribed CPFX from week 7 to week 32. RESULTS: Fourteen patients completed this 32-week study. The PDAI scores of eight patients decreased below seven. The mean total PDAI scores decreased significantly from 11 ± 2.5 to 6.5 ± 2.5 (P < 0.001). The mean value of total CPFX dose decreased significantly from 491.6 ± 182.4 mg/kg to 392.5 ± 184.0 mg/kg (P < 0.05). No severe adverse events were noted. CONCLUSIONS: Our data suggest that HST has a positive effect on chronic pouchitis with no adverse effects.

Associations Between the Prognostic Nutritional Index and Morbidity/Mortality During Intestinal Resection in Patients with Ulcerative Colitis.

BACKGROUND: Onodera's prognostic nutritional index (O-PNI) is a well-known predictor of the prognosis of several surgeries. The aim of this study was to evaluate the association between O-PNI and surgical outcome during surgery for ulcerative colitis (UC). METHODS: This was a single-institution retrospective cohort study conducted in the Department of Inflammatory Bowel Disease at Hyogo College of Medicine, Japan. The preoperative predictive factors associated with mortality, morbidity, and pouch-related complications (PRCs) were examined separately from surgical procedure. RESULTS: A total of 1151 patients with UC who underwent surgery between January 2000 and December 2015 were included. Total colectomy (TC) alone, ileal pouch-anal anastomosis (IPAA) with ileostomy, and IPAA without ileostomy were performed in 254 patients, 736 patients, and 161 patients, respectively. Mortality and morbidity were found in nine (0.8%) and 320 (27.8%) patients, respectively. The median O-PNI score was 22.6 in patients with mortality and 35.6 in patients without mortality among TC alone (p < 0.01). The significant predictive factors for mortality among TC alone were older age [p = 0.03, odds ratio (OR) 6.8], higher C-reactive protein (p = 0.02, OR 14.5), and O-PNI < 24.9 (p = 0.04, OR 5.6). Among IPAA with ileostomy, an American Society of Anesthesiologists score ≥3 (p = 0.01, OR 2.3), prednisolone (PSL) dosage just before surgery ≥14 mg/day (p = 0.04, OR 1.8), and O-PNI < 35.5 (p < 0.01, OR 2.1) were predictors of PRCs. O-PNI did not predict PRCs among IPAA without ileostomy. CONCLUSION: Lower O-PNI may predict the prognosis in patients with UC. O-PNI may be a useful indicator for decision-making regarding surgical timing and procedure.

Rectal-sparing type of ulcerative colitis predicts lack of response to pharmacotherapies.

BACKGROUND: Ulcerative colitis (UC) is known as an immune disorder of the colon that generally involves the rectum, but an atypical distribution of inflamed mucosa has previously been noted in certain subtypes of UC, such as the rectal-sparing type (RST). As noted in a previous report, patients with the RST may be at elevated risk for disease refractoriness, but the clinical significance of RST remains unknown. METHODS: UC patients who underwent surgery between January 2010 and April 2015 were included. Patients were classified as having the RST or a non-RST based on colectomy specimens or a pre-operative endoscopy. Possible risk factors for urgent/emergent surgery were analyzed. We specifically determined whether the RST is a significant predictor for urgent/emergent surgery. RESULTS: In total, 46/482 patients were classified as having the RST. Disease severity was significantly worse in patients with the RST than in other patients (p = 0.02). Urgent/emergent surgery was required for 24/46 patients with the RST, compared with 107/436 non-RST patients (p < 0.01). The overall incidence of urgent/emergent surgery was 131/482. Disease duration < 70.2 months [odds ratio (OR) 2.45], severe disease (OR 87.1), total administered steroid dose < 5000 mg (OR 3.02), daily pre-operative steroid dose ≥ 9 mg (OR 2.59), and the RST (OR 5.59) were identified as independent risk factors for urgent/emergent surgery. CONCLUSION: The RST was an independent risk factor for urgent/emergent surgery in our analysis of surgically treated patients with UC.

Is An Ostomy Rod Useful for Bridging the Retraction During the Creation of a Loop Ileostomy? A Randomized Control Trial.

BACKGROUND: A loop ileostomy is generally created during restorative proctocolectomy (RPC) for treating ulcerative colitis (UC), and an ostomy rod is often used to prevent stoma retraction. However, its usefulness or harmfulness has not been proven. We performed a prospective randomized control study to investigate the non-inferiority of ostomy creation without a rod to prevent stoma retraction. METHODS: Patients with UC who underwent RPC were enrolled and randomly divided into groups either with or without ostomy rod use. Incidences of stoma retraction and dermatitis were compared. RESULTS: Of the 320 patients in the study groups, 308 qualified for the intention-to-treat (ITT) analysis, and 257 were included in the per-protocol (PP) analysis. Ostomy retraction was recognized in 6 patients, 3 with a rod and 3 without. The difference with rod use (95% confidence interval) was 0.1 (-2.9 to 3.1)% in the PP analysis and 0.0 (-2.2 to 2.2)% in the ITT analysis. There were no significant differences in stoma retraction regardless of whether an ostomy rod was used in either analysis. Dermatitis was more common in patients with rod use (84/154) than in those without (40/154) (p < 0.01). CONCLUSIONS: Although median body mass indices were extremely low (20 kg/m2), an ostomy rod is not routinely needed as it may increase the risk of dermatitis. However, results in obese patients may differ from those shown here, which should be clarified via further studies.

Association between serum tumor necrosis factor-alpha level and the efficacy of infliximab for refractory pouchitis after restorative proctocolectomy in patients with ulcerative colitis.

OBJECTIVES: Although the aetiology of pouchitis after restorative proctocolectomy in ulcerative colitis (UC) remains unknown, infliximab (IFX) is often effective for this condition. However, indicators and predictors of treatment efficacy remain unclear. In this study, the association between serum tumor necrosis factor-alpha (TNF-α) levels and refractory pouchitis was evaluated. METHODS: We conducted a prospective study between January 2014 and April 2016. Patients with antibiotic-refractory pouchitis were treated with IFX. Serum TNF-α levels were measured before IFX induction. Diagnoses were confirmed using the modified Pouchitis Disease Activity Index (m-PDAI). Responders were defined as patients with an m-PDAI score lower than 5. Recurrence was defined as an m-PDAI score exceeding 5 during maintenance treatment or a need for additional treatments. Associations between serum TNF-α level and efficacy of IFX during 52 weeks of maintenance therapy were evaluated. RESULTS: Thirteen patients were eligible for this study. The short-term efficacy was 8/13 (61.5%). Four patients could not be maintained with IFX alone. The cumulative maintenance ratio was 30.8%/52 weeks, and the cut-off value for serum TNF-α was 1.93 pg/mL for short-term response. Although there was no significant association between serum TNF-α and treatment response, IFX treatment was unsuccessful for all five patients with TNF-α levels below 1.93 pg/mL, including four short-term non-responders and one long-term non-responder. CONCLUSION: Serum TNF-α level was not an independent predictor of IFX efficacy for refractory pouchitis. However, IFX may be effective for patients with elevated serum TNF-α. Future studies should assess this possibility.

Clinicopathological characteristics of cancer associated with Crohn's disease.

PURPOSE: We examined the clinicopathological characteristics and prognosis of patients with cancer associated with Crohn's disease (CD). METHODS: The subjects of this study were patients with cancer confirmed in a resected specimen of bowel, who were treated at our institution between September, 1974 and December, 2014. RESULTS: We analyzed 34 patients (26 men, 8 women, median age at cancer diagnosis 43.5 years, duration of illness 18 years) and found that the number of those with CD complicated with cancer began to drastically increase after 2005. The site of onset of cancer was in an anorectal lesion in 24 (70.6 %) patients. In 17 (50 %) patients, the cancer was diagnosed before surgery; in 3 patients (8.8 %), it was based on pathological findings during surgery; and in 14 patients (41.2 %), it was based on postoperative pathological findings. Mucinous carcinoma was the dominant histological type, seen in 15 patients (44.1 %), while the special type of signet-ring cell carcinoma was found in 4 patients. The cumulative overall 5 year survival rate was 46.2 %. CONCLUSION: In this group of Japanese CD patients, an anorectal lesion was the most frequent site of origin of cancer. As cancer was diagnosed preoperatively in only 50 % of these patients, the overall prognosis was poor, with a cumulative 5 year survival rate of just 46.2 %.

Long-term outcomes and sex differences after restorative proctocolectomy in pediatric patients with ulcerative colitis.

BACKGROUND: Restorative proctocolectomy (RPC) for ulcerative colitis (UC) could result in a higher patient quality of life, avoiding frequent disease flares; however, pouch failures and pouch-related complications (PRCs) can develop. PURPOSE: No cohort studies have examined pouch failure and the differences between adult and pediatric patients or the sex differences in pediatric UC. Therefore, the pouch failure rates were compared between adults and pediatric patients, and pouch failure and PRCs in pediatric UC were evaluated. METHODS: UC patients who underwent RPC between January 1987 and June 2014 at Hyogo College of Medicine were included. Patient background characteristics, PRCs, and pouch failure were reviewed. RESULTS: A total of 1347 adult UC patients and 90 (51 boys, 39 girls) pediatric UC patients were included in the study. The cumulative rate of pouch failure at 10years after RPC was significantly higher in pediatric UC (9.5%) than in adult UC (2.1%; p<0.01). In pediatric UC, the independent risk factors for pouch failure were pouchitis (hazard ratio (HR) 19.3) and anal fistula (HR 5.5). Although a sex difference was not seen in pouch failure, an independent risk factor for PRCs was being a girl (HR 2.5). CONCLUSIONS: Pouch failure was more common in pediatric than in adult UC. PRCs after RPC were more common in girls in pediatric UC.

Intra-operative gaps affect outcome and postoperative kinematics in vivo following cruciate-retaining total knee arthroplasty.

PURPOSE: The following investigation evaluates the effect of intra-operative gaps after posterior cruciate ligament-retaining total knee arthroplasty using two-dimensional/three-dimensional registration and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). METHODS: Patients were divided into two groups according to their 90°-0° component gap changes using a device designed by our laboratory. The wide gap group was defined as more than 3 mm (4.3 ± 0.7 mm), and the narrow gap group was defined as less than 3 mm (1.3 ± 1.3 mm). RESULTS: Under non-WB (weight bearing) conditions, the wide flexion gap group (N = 10) showed a significant anterior displacement of the medial femoral condyle as compared with the narrow flexion gap group (N = 20). Despite no significant differences observed under WB conditions, both femoral condyle positions during flexion were significantly more posterior than during extension. WOMAC of the tight gap group showed worse scores for two functional items demanding knee flexion (bending to floor and getting on/off toilet). CONCLUSION: The large flexion gap could influence the late rollback under non-WB conditions and better WOMAC functional scores in the flexion items. Three to four millimetre laxity at 90°-0° component gaps may be adequate and might be necessary to carry out daily life activities.

Clinical Features of Refractory Pouchitis with Penetrating Lesions and the Efficacy of Infliximab Treatment for Patients with Ulcerative Colitis after Restorative Proctocolectomy.

BACKGROUND: Chronic pouchitis with penetrating anal lesions often leads to pouch failure after restorative proctocolectomy. The aim of this study was to analyze those predictors and to evaluate the effects of infliximab (IFX). METHODS: We reviewed patients' backgrounds and performed a prospective trial of IFX treatment. Possible pre-operative factors were analyzed. Efficacy was assessed by comparing the pouchitis disease activity index (PDAI) and peri-anal DAI. Long-term efficacy was assessed via the rate of pouch failure. RESULTS: A total of 41 patients with refractory pouchitis were included. Although the patients with penetrating lesions were younger than those without, neither predictive pre-operative factors nor a correlation of C-related protein levels were observed. A total of 10 patients with penetrating lesions were enrolled for IFX treatment. Although the PDAI and peri-anal DAI decreased significantly (p = 0.04 and p = 0.02, respectively), the primary non-responders during the induction of IFX were 3 patients with obvious abscesses. The 1-year cumulative pouch failure rate was 0% in patients without abscesses and 50% in patients with abscesses under IFX maintenance. CONCLUSIONS: IFX treatment for refractory pouchitis with penetrating complications appears to be effective. However, once penetrating lesions develop to abscesses, these lesions are difficult to heal.

Does Pre-Operative Multiple Immunosuppressive Therapy Associate with Surgical Site Infection in Surgery for Ulcerative Colitis.

BACKGROUND: Almost all surgeries for ulcerative colitis (UC) are performed under immunosuppressive conditions. Immunomodulators or biologics, with the exception of corticosteroids, do not appear to be risk factors for post-operative infectious complications. However, many patients are on multiagent immunosuppressive therapy at the time of surgery. Therefore, we evaluated the influence of pre-operative multiple immunosuppressives on the occurrence of surgical site infection (SSI) in UC. METHODS: We reviewed surveillance data from 181 patients who underwent restorative proctocolectomy between January 2012 and March 2014. The incidences of SSI and the possible risk factors among patients receiving different immunosuppressive therapies were compared and analyzed. RESULTS: The incidence of incisional (INC) SSI was 13.3% and that of organ/space (O/S) SSI was 7.2%. The number of immunosuppressives did not significantly correlate with each incidence. Total prednisolone administration ≥12,000 mg (OR 2.6) and an American Society of Anesthesiologists score ≥3 (OR 2.8) were shown to be independent risk factors for overall SSI, whereas corticosteroid use in INC SSI (OR 17.4) and severe disease (OR 5.2) and a large amount of blood loss (OR 3.9) in O/S SSI were identified as risk factors. CONCLUSION: Although a correlation between multiple immunosuppressive therapy and SSIs was not found, it is not recommended that all patients be treated with multiple immunosuppressive therapy. Treatment strategy should be applied based on the patient's condition.

Surgery for Severe Ulcerative Colitis during Pregnancy: Report of Two Cases.

Refractory ulcerative colitis (UC) that does not respond to medical therapy often requires surgery even during pregnancy. Although surgical cases of UC during pregnancy were reported previously, the standard surgical strategy for both colitis and pregnancy was unclear. Herein, fetal and maternal safety as well as the strategy for this unusual surgical procedure during pregnancy in patients with UC are considered. A 28-year-old woman was diagnosed with left-sided moderate UC at 12 weeks of pregnancy; toxic megacolon was suspected, and surgery was required. Although the baby's gestational age was 23 weeks and 3 days, a cesarean section was performed before the colectomy. In a next case, a 28-year-old woman had a 2-year history of left-sided UC. Her colitis flared up at 11 weeks of pregnancy. Colectomy was performed because her colitis was unresponsive to conservative therapy, and the pregnancy was continued, with a transvaginal delivery at 36 weeks. In patients with UC, the need for surgery should be determined promptly based on disease severity, whether or not the patient is pregnant. The need for surgery should not be affected by pregnancy. The pregnancy should be continued for as long as possible when there are no fetal and maternal complications. Both cesarean section and colectomy should be performed independently if necessary.

Clinical features and treatment of ulcerative colitis-related severe gastroduodenitis and enteritis with massive bleeding after colectomy.

INTRODUCTION: Ulcerative colitis (UC) has been recognised as a systemic immune disorder that is not as restricted as colitis. UC-related gastrointestinal lesions with bleeding can develop soon after colectomy and can progress rapidly. Therefore, we considered the clinical features and treatment of these UC-related lesions. METHODS: We reviewed the patient data in our UC surgery database to evaluate its prevalence and features. RESULTS: We found 7/1,100 patients with UC-related lesions between January 2000 and April 2013. These lesions developed at a mean of 24 (range 8-480) days after colectomy. Six of the seven patients suffered from gastrointestinal bleeding as an initial symptom that rapidly developed into massive bleeding or perforations. All of the patients were diagnosed with pancolitis; at the time of colectomy, fulminant, severe, moderate, and mild colitis were presented by four, one, one, and one patients, respectively. All patients with enteritis had consecutively developed other infectious complications, including anastomotic leakage, pyoderma gangrenosum, wound infection, and pneumonia. Although patients with bleeding did not respond to treatment with corticosteroids, they responded well to infliximab soon after its administration. Although six of the seven patients showed cytomegalo virus re-activation in blood or pathological examinations, ganciclovir was not effective in its elimination. CONCLUSION: Although UC-related lesions with an unknown aetiology can occur after colectomy, immediate examination and treatment are required if gastrointestinal bleeding is found after surgery. Because gastrointestinal bleeding from UC-related lesions can worsen rapidly and may be related to mortality, early potent immunosuppressive therapy should be considered.