Hyperactive Distal Colonic Motility and Recovery Patterns Following Right Colectomy: A High-Resolution Manometry Study.

BACKGROUND: Postoperative ileus results in morbidity, prolonged hospitalization, and increased health care expenditure. However, the underlying abnormalities in motility remain poorly understood. Recent high-resolution manometry studies demonstrated that the distal colon becomes hyperactive with a cyclic motor pattern postoperatively, but they did not track this activity beyond 16 hours after surgery. OBJECTIVE: This study used high-resolution manometry to evaluate distal colonic motility during the first 4 days after right-sided colectomy. DESIGN: An observational study of perioperative high-resolution colonic manometry using a 36-sensor catheter with 1-cm resolution. SETTING: A single tertiary hospital. PATIENTS: Adult patients undergoing elective laparoscopic or open right-sided colonic resection. MAIN OUTCOME MEASURES: Occurrence of distal colonic motor patterns during the perioperative period, defined according to a published classification system. Clinical markers of gut recovery included time to first stool, oral diet, and prolonged postoperative ileus. RESULTS: Seven patients underwent perioperative manometry recordings. Hyperactive cyclic motor patterns emerged intraoperatively and peaked in the first 12 hours postoperatively, occupying 81.8% ± 3.9% of the recording. This gradually returned to normal during the first 4 days, reaching 19.0% ± 4.4% ( p = 0.002). No patient had a bowel movement before this hyperactivity resolved. High-amplitude propagating sequences were absent in early postoperative recordings, and their return temporally correlated with the passage of stool. Abnormal high-amplitude repetitive 0.5 to 1 cycle per minute activity was observed in the left colon of 1 patient with prolonged ileus. LIMITATIONS: The invasive nature of recordings limited this study to a small sample size. CONCLUSIONS: Cyclic motor patterns are markedly hyperactive in the distal colon after right-sided colectomy and resolve during the first 4 postoperative days. High-amplitude propagating sequences are inhibited by surgery and gradually recover. Bowel function may not return until these changes resolve. Other abnormal repetitive hyperactive patterns could contribute to the development of prolonged ileus. See Video Abstract at http://links.lww.com/DCR/B967 . MOTILIDAD HIPERACTIVA DEL COLON DISTAL Y PATRONES DE RECUPERACIN DESPUS DE COLECTOMA DERECHA UN ESTUDIO DE MANOMETRA DE ALTA RESOLUCIN: ANTECEDENTES:El íleo post-operatorio produce una morbilidad significativa, una hospitalización prolongada y un aumento del gasto sanitario. Sin embargo, las anomalías subyacentes en la motilidad siguen siendo poco conocidas. Estudios recientes de manometría de alta resolución demostraron que el colon distal se vuelve hiperactivo con un patrón motor cíclico en el post-operatorio, pero no registraron esta actividad más allá de las 16 horas posteriores a la cirugía.OBJETIVO:Utilizar la manometría de alta resolución para evaluar la motilidad del colon distal durante los primeros cuatro días después de la colectomía del lado derecho.DISEÑO:Estudio observacional de pacientes sometidos a manometría colónica perioperatoria de alta resolución mediante catéter de 36 sensores con 1 cm de resolución.AJUSTE:Un solo hospital terciario.PACIENTES:Pacientes adultos sometidos a resección laparoscópica o abierta de colon del lado derecho de forma electiva.PRINCIPALES MEDIDAS DE RESULTADO:AAparición de patrones motores del colon distal durante el período perioperatorio, definidos según un sistema de clasificación publicado. Los marcadores clínicos de recuperación intestinal incluyeron, tiempo hasta la primera evacuación, dieta oral e íleo posoperatorio prolongado.RESULTADOS:Siete pacientes fueron sometidos a registros de manometría perioperatoria. Los patrones motores cíclicos hiperactivos emergieron intraoperatoriamente y alcanzaron su punto máximo en las primeras 12 horas post-operatorias, ocupando 81,8 ± 3,9% del registro. Esto volvió gradualmente a la normalidad durante los primeros cuatro días, alcanzando el 19,0 ± 4,4% (p = 0,002). Ningún paciente tuvo una evacuación intestinal antes de que se resolviera esta hiperactividad. Las secuencias de propagación de alta amplitud estaban ausentes en las grabaciones post-operatorias tempranas y su retorno se correlacionó temporalmente con el paso de las heces. Se observó actividad anormal de alta amplitud repetitiva de 0,5-1 ciclo / minuto en el colon izquierdo de un paciente con íleo prolongado.LIMITACIONES:La naturaleza invasiva de las grabaciones limitó este estudio a un tamaño de muestra pequeño.CONCLUSIONES:Los patrones motores cíclicos son marcadamente hiperactivos en el colon distal después de la colectomía del lado derecho y se resuelven gradualmente durante los primeros cuatro días posoperatorios. Las secuencias de propagación de gran amplitud se inhiben mediante cirugía y se recuperan gradualmente. Es posible que la función intestinal no regrese hasta que estos cambios se resuelvan. Otros patrones hiperactivos repetitivos anormales podrían contribuir al desarrollo de íleo prolongado. Consulte Video Resumen en http://links.lww.com/DCR/B967 . (Traducción-Dr. Mauricio Santamaria ).

Faecal incontinence is associated with an impaired rectosigmoid brake and improved by sacral neuromodulation.

BACKGROUND: The rectosigmoid brake, characterised by retrograde cyclic motor patterns on high-resolution colonic manometry, has been postulated as a contributor to the maintenance of bowel continence. Sacral neuromodulation (SNM) is an effective therapy for faecal incontinence, but its mechanism of action is unclear. This study aims to investigate the colonic motility patterns in the distal colon of patients with faecal incontinence, and how these are modulated by SNM. METHODS: A high-resolution fibreoptic colonic manometry catheter, containing 36 sensors spaced at 1-cm intervals, was positioned in patients with faecal incontinence undergoing stage 1 SNM. One hour of pre- and post meal recordings were obtained followed by pre- and post meal recordings with suprasensory SNM. A 700-kcal meal was given. Data were analysed to identify propagating contractions. RESULTS: Fifteen patients with faecal incontinence were analysed. Patients had an abnormal meal response (fewer retrograde propagating contractions compared to controls; p = 0.027) and failed to show a post meal increase in propagating contractions (mean 17 ± 6/h premeal vs. 22 ± 9/h post meal, p = 0.438). Compared to baseline, SNM significantly increased the number of retrograde propagating contractions in the distal colon (8 ± 3/h premeal vs. 14 ± 3/h premeal with SNM, p = 0.028). Consuming a meal did not further increase the number of propagating contractions beyond the baseline upregulating effect of SNM. CONCLUSION: The rectosigmoid brake was suppressed in this cohort of patients with faecal incontinence. SNM may exert a therapeutic effect by modulating this rectosigmoid brake.

Prolonged postoperative ileus following right- versus left-sided colectomy: A systematic review and meta-analysis.

AIM: Prolonged postoperative ileus (PPOI) is a common complication following colonic surgery, and is associated with longer hospital stay, greater risk of complications and substantial cost for patients and hospitals. Some reports have recently suggested that gastrointestinal (GI) recovery varies based on the side of resection (i.e., right-sided vs. left-sided colectomy). This systematic review and meta-analysis aimed to compare GI recovery by resection side. METHODS: The MEDLINE, Embase, Cochrane Library and CENTRAL databases were systematically searched for articles reporting GI recovery outcomes in adults undergoing elective right- versus left-sided colectomy (excluding with ileostomy) of any surgical approach. The primary outcome was PPOI, and secondary outcomes included time to first passage of flatus, stool and tolerance of solid diet, and postoperative complications. Subgroup analyses of laparoscopic procedures and cohorts without inflammatory bowel disease and sensitivity analysis of adjusted multivariate results were also performed. RESULTS: Nine studies were identified, of which seven were included in the meta-analysis, comprising 29 068 colectomies (14 581 right-sided; 14 487 left-sided). PPOI was heterogeneously defined and was significantly more likely following right-sided compared to left-sided colectomy regardless of the surgical approach (OR 1.78, 95% CI 1.32-2.39; P < 0.01; I2  = 51%), as well as on subgroup analyses and adjusted multivariate meta-analysis. Secondary outcomes were reported in only a few small studies; hence meta-analysis did not produce reliable results. CONCLUSION: Based on heterogeneous definitions, consistently higher rates of PPOI were observed following right- versus left-sided colectomy. These differences are currently unexplained and highlight the need for further research into the pathophysiology of ileus.

Validation of body surface colonic mapping (BSCM) against high resolution colonic manometry for evaluation of colonic motility.

Abnormal cyclic motor pattern (CMP) activity is implicated in colonic dysfunction, but the only tool to evaluate CMP activity, high-resolution colonic manometry (HRCM), remains expensive and not widely accessible. This study aimed to validate body surface colonic mapping (BSCM) through direct correlation with HRCM. Synchronous meal-test recordings were performed in asymptomatic participants with intact colons. A signal processing method for BSCM was developed to detect CMPs. Quantitative temporal analysis was performed comparing the meal responses and motility indices (MI). Spatial heat maps were also compared. Post-study questionnaires evaluated participants' preference and comfort/distress experienced from either test. 11 participants were recruited and 7 had successful synchronous recordings (5 females/2 males; median age: 50 years [range 38-63]). The best-correlating MI temporal analyses achieved a high degree of agreement (median Pearson correlation coefficient (Rp) value: 0.69; range 0.47-0.77). HRCM and BSCM meal response start and end times (Rp = 0.998 and 0.83; both p < 0.05) and durations (Rp = 0.85; p = 0.03) were similar. Heat maps demonstrated good spatial agreement. BSCM is the first non-invasive method to be validated by demonstrating a direct spatio-temporal correlation to manometry in evaluating colonic motility.

Hierarchically assembled one-dimensional TiO2 nanostructures: echinoid- and labyrinth-shaped TiO2 crystals for dye sensitized solar cell.

TiO2 nanostructures have been studied intensively for decades for their photocatalytic properties. Recently, several interesting TiO2 nanostructures with controlled surface facets or shapes were reported. However, systemic approaches to obtain designed nanostructures are still rare. Here, various hierarchical 1D TiO2 nanostructures, including TiO2 nanorods, echinoid-shaped TiO2, and labyrinth-structured TiO2, were fabricated by a one-pot hydrothermal process. Concentrated HCl was added to a solution having a Ti4+/H+ ratio that ranged from 1/4 to 1/8. The highly concentrated acid stabilized hydrolysis and hindered condensation, thereby balancing nucleation and growth of TiO2 nanostructures in the hydrothermal treatment step. Dye-sensitized solar cells prepared using the hierarchical 1D TiO2 nanostructures have shown higher photon to current conversion efficiency in the wavelength over 600 nm compared to those prepared with TiO2 nanoparticles.

Post-operative ileus: definitions, mechanisms and controversies.

Post-operative ileus (POI) is a syndrome of impaired gastrointestinal transit which occurs following abdominal surgery. There are few effective targeted therapies for ileus, and research has been limited by inconsistent definitions and an incomplete understanding of the underlying pathophysiology. Despite considerable effort, there remains no widely-adopted definition of ileus, and recent work has identified variation in outcome reporting is a major source of heterogeneity in clinical trials. Outcomes should be clearly-defined, clinically-relevant, and reflective of the underlying biology, impacts on hospital resources and quality of life. Further collaborative efforts will be needed to develop consensus definitions and a core outcome set for postoperative gastrointestinal recovery. Investigation into the pathophysiology of POI has been hindered by use of low-resolution techniques and difficulties linking cellular mechanisms to dysmotility patterns and clinical symptoms. Recent evidence has suggested the common assumption of post-operative GI paralysis is incorrect, and that the distal colon becomes hyperactive following surgery. The post-operative inflammatory response is important in the pathophysiology of ileus, but the time course of this in humans remains unclear, with the majority of evidence coming from animal models. Future work should investigate dysmotility patterns underlying ileus, and identify biomarkers which may be used to diagnose, monitor and stratify patients with ileus.

Variable Gut Function Recovery After Right vs. Left Colectomy May Be Due to Rectosigmoid Hyperactivity.

It is established that gut function recovers slower after right vs. left colectomies with higher rates of prolonged post-operative ileus (PPOI), but the reason is unclear. Development of PPOI is multifactorial. A recent manometry study in right colectomy patients showed that the distal colon becomes hyperactive after surgery with predominantly cyclic motor patterns (CMPs). In this perspective, we evaluate the hypothesis that the slower gut recovery after right hemicolectomy could be induced by a functional obstruction due to hyperactive CMPs.