Clinical endpoint, early detection, and differential diagnosis of postoperative ileus: a systematic review of the literature

Early Small Bowel Obstruction Caused by Surgical Drain Following Rectal Cancer Surgery: A Case Report

The abdominal drains are commonly used and could be a source of several complications, including infection and small bowel obstruction. We report the case of a 70-year-old male patient with intestinal obstruction related to abdominal drainage after rectal surgery. Acute bowel obstruction remains a rare complication of abdominal drains. Surgeons should be aware of this situation and use drains with caution. The treatment options include conservative treatment or surgery either a laparoscopic approach or laparotomy.

Surgical Drain-Related Small Bowel Obstruction After Open Radical Cystoprostatectomy: A Case Report

Surgical drains are commonly used to manage intraperitoneal fluid after major surgeries, but their prophylactic use has been controversial due to potential complications. One rarely reported complication is small bowel obstruction (SBO), primarily seen in post-colorectal surgeries. We present a case of SBO following open radical cystectomy due to surgical drain placement, a complication not previously reported in urologic surgeries. The case highlights the importance of considering the risks and benefits of prophylactic drain placement. It emphasizes the need for a higher index of suspicion for SBO in patients with surgical drains who develop post-operative nausea and distention. Timely radiological imaging and clinical examination are crucial for accurate diagnosis and proper treatment.

Rectal stimulation with prebiotics and probiotics before ileostomy reversal: a study protocol for a randomized controlled trial

BACKGROUND

Ileostomy closure is associated with a high rate of postoperative morbidity, and adynamic ileus is the most common complication, with an incidence of up to 32%. This complication is associated with delayed initiation of oral diet intake, abdominal distention, prolonged hospital stay, and more significant patient discomfort. The present study aims to evaluate the rectal stimulus with prebiotics and probiotics before ileostomy reversal.

METHODS

This is a protocol study for an open-label randomized controlled clinical trial. Ethical approval was received (CAAE: 56551722.6.0000.0071). The following criteria will be used for inclusion: adult patients with rectal cancer stages cT3/4Nx or cTxN+ that underwent loop protection ileostomy, patients treated with neoadjuvant chemoradiotherapy, and patients who underwent laparoscopic or robotic total mesorectal excision. Patients will be randomized to one of two groups. The intervention group (with rectal stimulus): the patients will apply 500 ml of saline solution with 6 g of Simbioflora® rectally, once a day, for 15 days before ileostomy closure. The control group (without rectal stimulation): the patients will close the ileostomy with no previous rectal stimulus. The primary outcomes will be the adynamic ileus (need for postoperative nasogastric tube insertion; nausea/vomiting; or intolerance to oral feedings within the first 72 h) and intestinal transit (time to first evacuation/flatus).

RESULTS

The patient's enrollment starts in January 2023. We expect to finish in July 2025.

DISCUSSION

The findings of this randomized clinical study may have important implications for managing patients undergoing ileostomy reversal.

TRIAL REGISTRATION

This study is registered in the Brazilian Trial Registry (ReBEC) under RBR-366n64w. Registration date: 19/07/2022.

Electroacupuncture versus sham electroacupuncture in the treatment of postoperative ileus after laparoscopic surgery for colorectal cancer: study protocol for a multicentre, randomised, sham-controlled trial

INTRODUCTION

Postoperative ileus (POI) is an inevitable complication of almost all abdominal surgeries, which results in prolonged hospitalisation and increased healthcare costs. Various treatment strategies have been developed for POI but with limited success. Electroacupuncture (EA) might be a potential therapy for POI. However, evidence from rigorous trials that evaluated the effectiveness of EA for POI is limited. Thus, the aim of this study was to examine whether EA can safely reduce the time to the first defecation after laparoscopic surgery in patients with POI.

METHODS AND ANALYSIS

This multicentre randomised sham-controlled trial will be conducted in four hospitals in China. A total of 248 eligible participants with colorectal cancer who will undergo laparoscopic surgery will be randomly allocated to an EA group and a sham EA group in a 1:1 ratio. Treatment will be performed starting on postoperative day 1 and continued for four consecutive days, once per day. If the participant is discharged within 4 days after surgery, the treatment will cease on the day of discharge. The primary outcome will be the time to first defecation. The secondary outcome measures will include time to first flatus, tolerability of semiliquid and solid food, length of postoperative hospital stay, postoperative nausea and vomiting, abdominal distension, postoperative pain, postoperative analgesic, time to first ambulation, blinding assessment, credibility and expectancy and readmission rate.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics Committee of Beijing University of Chinese Medicine (number 2020BZHYLL0116) and the institutional review board of each hospital. The results will be disseminated through peer-reviewed publications. This study protocol (V.3.0, 6 March 2020) involves human participants and was approved by the ethics committees of Beijing University of Chinese Medicine (number 2020BZHYLL0116), Beijing Friendship Hospital Affiliated to Capital Medical University (number 2020-P2-069-01), Beijing Chao-Yang Hospital Affiliated to Capital Medical University (number 2020-3-11-2), National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College (number 20/163-2359), and the Affiliated Hospital of Qingdao University (number QYFYKYLL711311920). The participants gave informed consent to participate in the study before taking part.

TRIAL REGISTRATION NUMBER

ChiCTR2000038444.

A Role for Gastric Point of Care Ultrasound in Postoperative Delayed Gastrointestinal Functioning

INTRODUCTION

Delayed bowel function (DBF) and postoperative ileus (POI) are common gastrointestinal complications after surgery. There is no reliable imaging study to help diagnose these complications, forcing clinicians to rely solely on patient history and physical exam. Gastric point of care ultrasound (POCUS) is a simple bedside imaging technique to evaluate gastric contents but has not been evaluated in postoperative patients.

METHODS

Twenty colorectal patients were enrolled in this pilot study. Patients were categorized as either full or empty stomach based upon their postoperative day one gastric POCUS exams and previously published definitions. The primary outcome was GI-3 recovery, a dual end point defined as tolerance of solid food and either flatus or bowel movement. Secondary outcomes were length of stay, emesis, time to first flatus, time to first bowel movement, nasogastric tube placement, aspiration events, and mortality.

RESULTS

Nine of 20 patients had a full stomach postoperatively. Patients with full stomachs were younger and received greater perioperative opioid doses (74.0 ± 28.2 v 42.6 ± 32.9 morphine equivalents, P = 0.0363) compared to empty stomach patients. GI-3 recovery occurred significantly later for patients with postoperative day 1 full stomachs (2.1 ± 0.4 versus 1 ± 0 days, P = 0.00091).

CONCLUSIONS

Based upon this pilot study, gastric POCUS may hold promise as a noninvasive and simple bedside modality to potentially help identify colorectal patients at risk for postoperative DBF and POI and should be evaluated in a larger study.

Omitting nasogastric tube placement after gastrectomy does not enhance postoperative recovery: a propensity score matched analysis

PURPOSE

Enhanced recovery after surgery (ERAS) program has become the main trend in gastrointestinal surgery. This study aims to investigate factors influencing the decision-making of nasogastric tube (NGT) placement and its safety and efficacy after gastrectomy.

METHODS

We analyzed our prospectively maintained database including 287 patients who underwent elective gastrectomy in our department from January 1 to December 31, 2017. All cases were divided into two groups, namely, the no-NGT group and the NGT group. Logistic regression was used to analyze factors that affected the decision of NGT placement, and propensity score matching (PSM) was later applied to balance those factors for the analysis of safety outcomes between groups.

RESULTS

Multivariate analysis showed resection range (p = 0.004, proximal gastrectomy: OR = 4.555, 95%CI = 1.392-14.905, p = 0.016; total gastrectomy: OR = 1.990, 95%CI = 1.205-3.287, p = 0.009) was the only independent risk factor of NGT placement. NGT was omitted in the majority (58.8%) of distal gastrectomy but only in 42.5% and 25% in total and proximal gastrectomy. After PSM, we found no significant differences between patients with or without NGT in postoperative hospital stay, time to first flatus and defecation, time to fluid and semi-fluid diet, rate of reinsertion, or hospitalization expenditure (p > 0.05, respectively). The incidence of postoperative complications in the two groups were 21.7% and 23.5%, respectively (p = 0.753), and the incidence of major complications was 7.0% and 9.6% (p = 0.472).

CONCLUSION

The decision-making of NGT placement is mainly influenced by the resection range. Omitting NGT is a safe approach in all types of gastrectomy but was not able to enhance the recovery in our practice.

State-of-the-art colorectal disease: postoperative ileus

PURPOSE

Postoperative Ileus (POI) remains an important complication for patients after abdominal surgery with an incidence of 10-27% representing an everyday issue for abdominal surgeons. It accounts for patients' discomfort, increased morbidity, prolonged hospital stays, and a high economic burden. This review outlines the current understanding of POI pathophysiology and focuses on preventive treatments that have proven to be effective or at least show promising effects.

METHODS

Pathophysiology and recommendations for POI treatment are summarized on the basis of a selective literature review.

RESULTS

While a lot of therapies have been researched over the past decades, many of them failed to prove successful in meta-analyses. To date, there is no evidence-based treatment once POI has manifested. In the era of enhanced recovery after surgery or fast track regimes, a few approaches show a beneficial effect in preventing POI: multimodal, opioid-sparing analgesia with placement of epidural catheters or transverse abdominis plane block; μ-opioid-receptor antagonists; and goal-directed fluid therapy and in general the use of minimally invasive surgery.

CONCLUSION

The results of different studies are often contradictory, as a concise definition of POI and reliable surrogate endpoints are still absent. These will be needed to advance POI research and provide clinicians with consistent data to improve the treatment strategies.

Paralytic ileus in the United States: A cross-sectional study from the national inpatient sample

Introduction:

Paralytic ileus is a common clinical condition leading to significant morbidity and mortality. Most studies to date have focused on postoperative ileus, a common but not exclusive cause of the condition. There are limited epidemiological data regarding the incidence and impact of paralytic ileus and its relationship to other clinical conditions. In this cross-sectional study, we analyzed national inpatient hospitalization trends, demographic variation, cost of care, length of stay, and mortality for paralytic ileus hospitalizations as a whole.

Methods:

The National Inpatient Sample database was used to identify all hospitalizations with the diagnosis of paralytic ileus (International Classification of Diseases, 9th Revision code 560.1) as primary or secondary diagnosis during the period from 2001 to 2011. Statistical analysis was performed using Cochran–Armitage trend test, Wilcoxon rank sum test, and Poisson regression.

Results:

In 2001, there were 362,561 hospitalizations with the diagnosis of paralytic ileus as compared to 470,110 in 2011 (p < 0.0001). The age group 65–79 years was most commonly affected by paralytic ileus throughout the study period. In-hospital all-cause mortality decreased from 6.03% in 2001 to 5.10% in 2011 (p < 0.0001). However, the average cost of care per hospitalization increased from US$19,739 in 2001 to US$26,198 in 2011 (adjusted for inflation, p < 0.0001).

Conclusion:

There was a significant rise in the number of hospitalizations of paralytic ileus with increased cost of care and reduced all-cause mortality.

Pretreatment with transcutaneous electrical acupoint stimulation to prevent postoperative ileus in patients undergoing laparoscopic colon surgery: study protocol for a randomised controlled trial

INTRODUCTION

Postoperative ileus (POI), a common complication after surgery, severely affects postoperative recovery. It is unclear whether pretreatment with transcutaneous electrical acupoint stimulation (TEAS) can improve recovery from POI. This trial will evaluate the effects of pretreatment with TEAS on POI.

METHODS AND ANALYSIS

This will be a prospective, randomised controlled trial. American Society of Anesthesiologists (ASA) physical status classification I-III level patients, aged 18-75 years and scheduled for laparoscopic colon surgery, will be included in the study. It is planned that 146 subjects will be randomised to the TEAS and sham TEAS (STEAS) groups. The groups will undergo two sessions of TEAS/STEAS daily for 3 days before surgery, with a final TEAS/STEAS treatment 30 min before anaesthesia. The primary endpoint of the study will be time to first defaecation. Secondary endpoints will include time to first flatus, time to tolerance of oral diet, GI-2 (composite outcome of time to first defaecation and time to tolerance of oral diet), time to independent walking, length of hospital stay, postoperative pain Visual Analogue Scale score on the first 3 days after surgery, analgesic requirements, complications and plasma concentrations of interferon-β (IFN-β), IFN-γ, interleukin-6 (IL-6) and IL-1β. Multiple linear regression will be used to identify independent predictors of outcome measures.

ETHICS AND DISSEMINATION

This study has been approved by the Chinese Registered Clinical Trial Ethics Review Committee (No. ChiECRCT-20170084). The results of the trial will be published in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

This study has been registered with the Chinese Clinical Trial Registry (No. ChiCTR-INR-17013184).

TRIAL STATUS

The study was in the recruitment phase at the time of manuscript submission.

The value of the erect abdominal radiograph for the diagnosis of mechanical bowel obstruction and paralytic ileus in adults presenting with acute abdominal pain

INTRODUCTION

There is discord on the value of the erect abdominal radiograph for diagnosing acute abdominal pathologies. The erect radiograph can be uncomfortable for patients in pain and increases patient radiation dose.

AIM

To determine if including the erect abdominal radiograph in plain abdominal radiography (PAR) improved diagnostic accuracy for identifying mechanical bowel obstruction and/or paralytic ileus in adults presenting with acute abdominal pain.

METHODS

PAR of 40 consecutive adults presenting with suspected bowel obstruction or paralytic ileus was retrospectively sampled and independently reviewed by two emergency department (ED) consultants and two radiology consultants for bowel obstruction and paralytic ileus across two sessions. In session 1, the assessors assessed the supine abdominal radiographs (PAR 1) and clinical details in a randomised order, and session 2, at least 6 weeks later, they assessed the supine and erect radiographs (PAR 2) and clinical details of the randomly re-ordered cases. Computed tomography was the reference standard. Pair-wise comparisons of receiver operating characteristic curves were calculated to assess for significant differences in participants' diagnostic accuracy using MedCalc 16.4.3.

RESULTS

Average sensitivity, specificity and area under the receiver operating characteristic curves (AUROC) were 69.7%, 61.0% and 0.642 for PAR 1, respectively, and 80.0%, 53.4% and 0.632 for PAR 2 respectively. For AUROC there were no significant differences (P > 0.05) between PAR 1 and PAR 2. Intra-rater and inter-rater agreement improved in PAR 2.

CONCLUSION

There was no statistically significant improvement in diagnostic accuracy when including the erect radiograph in PAR for the acute abdomen.

Systemic Inflammatory Cytokines Predict the Infectious Complications but Not Prolonged Postoperative Ileus after Colorectal Surgery

Aim

Postoperative ileus (POI) is common after surgery. Animal studies indicate that the POI mechanism involves an inflammatory response, which is also activated during postoperative complications. This study aimed to determine whether inflammatory biomarkers might facilitate an early detection of prolonged POI (PPOI) or infectious complications.

Methods

Forty-seven adult patients who underwent oncological colorectal surgery were included. They filled out a perioperative diary to report their gastrointestinal symptoms. Blood samples were collected preoperatively, and on postoperative day (POD) 1 and 3. Levels of leucocytes, C-reactive protein (CRP), interleukin (IL)-6, TNF-α, and IL-1β were analyzed.

Results

Patients with PPOI had significantly longer stay in hospital than patients without (13.6 ± 10.5 versus 7.4 ± 3.2 days, p < 0.001); they also had higher levels of IL-6 ratios, leucocytes, and CRP levels, but did not reach significance. Higher levels of postoperative IL-6 and CRP levels (p < 0.05, resp.) were found in patients with infectious complications. The receiver operating characteristic (ROC) analysis found better diagnostic values of IL-6 ratio on both POD 1 and 3 than that of CRP (POD 1: ROC 0.825, p < 0.001).

Conclusion

Blood levels of inflammatory cytokines cannot predict PPOI after colorectal surgery. Instead, postoperative IL-6 changes may predict the infectious complications with a better diagnostic value than the current leukocytes or CRP tests.

Effectiveness of Acupuncture for Early Recovery of Bowel Function in Cancer: A Systematic Review and Meta-Analysis

Objectives

The aim of this study was to evaluate the effects of acupuncture therapy to reduce the duration of postoperative ileus (POI) and to enhance bowel function in cancer patients.

Methods

A systematic search of electronic databases for studies published from inception until January 2017 was carried out from six databases. Randomized controlled trials (RCTs) involving the use of acupuncture and acupressure for POI and bowel function in cancer patients were identified. Outcomes were extracted from each study and pooled to determine the risk ratio and standardized mean difference.

Results

10 RCTs involving 776 cancer patients were included. Compared with control groups (no acupuncture, sham acupuncture, and other active therapies), acupuncture was associated with shorter time to first flatus and time to first defecation. A subgroup analysis revealed that manual acupuncture was more effective on the time to first flatus and the time to first defecation; electroacupuncture was better in reducing the length of hospital stay. Compared with control groups (sham or no acupressure), acupressure was associated with shorter time to first flatus. However, GRADE approach indicated a low quality of evidence.

Conclusions

Acupuncture and acupressure showed large effect size with significantly poor or inferior quality of included trials for enhancing bowel function in cancer patients after surgery. Further well-powered evidence is needed.

A Systematic Review and Meta-Analysis of Acupressure for Postoperative Gastrointestinal Symptoms among Abdominal Surgery Patients

Postoperative ileus is a common and often life-threatening gastrointestinal complication with few management methods available for patients. Integrating acupressure into perioperative care promises to bring benefits into preventing postoperative ileus. This systematic review and meta-analysis aims to evaluate the efficacy of acupressure in identifying the signs and symptoms of postoperative ileus among patients undergoing abdominal surgery. The MEDLINE, EMBASE, Web of Science, CINAHL, China Journal Net and Wanfang databases were searched for high-quality RCTs using keywords such as acupressure, postoperative ileus, abdominal surgery, etc. A total of six studies ([Formula: see text]) were included in this review and meta-analysis. The quality of the literature was found to be uniformly moderate by the Effective Public Health Practice Project (EPHPP) assessment tool. The results of meta-analyses revealed that acupressure could significantly reduce risks for postoperative nausea (OR 0.52, 95% CI 0.39–0.70, [Formula: see text]) and vomiting (OR 0.54, 95% CI 0.39–0.75, [Formula: see text]) compared with the control group, without significant heterogeneity among studies. Meta-analysis of the need for antiemetic drugs suggested that the OR was 0.39 (95% CI 0.20–0.78, [Formula: see text]) with significant heterogeneity among studies. Our results suggested that acupressure might be effective in reducing the incidence of postoperative nausea and vomiting and the need for antiemetic drugs among patients undergoing abdominal surgery. Considering the substantial risk of bias in the articles included, future high-quality RCTs with a rigorous methodology are desirable to provide solid evidence. Furthermore, other signs and symptoms of postoperative ileus should be explored in future.

Comparison of multi-modal early oral nutrition for the tolerance of oral nutrition with conventional care after major abdominal surgery: a prospective, randomized, single-blind trial

Background & aims

Early oral nutrition (EON) has been shown to improve recovery of gastrointestinal function, length of stay and mortality after abdominal surgery; however, early oral nutrition often fails during the first week after surgery. Here, a multi-modal early oral nutrition program is introduced to promote recovery of gastrointestinal function and tolerance of oral nutrition.

Methods

Consecutive patients scheduled for abdominal surgery were randomized to the multimodal EON group or a group receiving conventional care. The primary endpoint was the time of first defecation. The secondary endpoints were outcomes and the cost-effectiveness ratio in treating infectious complications. The rate of infectious-free patients was regarded as the index of effectiveness.

Results

One hundred seven patients were randomly assigned to groups. Baseline characteristics were similar for both groups. In intention-to-treat analysis, the success rate of oral nutrition during the first week after surgery in the multimodal EON group was 44 (83.0%) versus 31 (57.4%) in the conventional care group (P = 0.004). Time to first defecation, time to flatus, recovery time of bowel sounds, and prolonged postoperative ileus were all less in the multimodal EON group (P < 0.05). The median postoperative length of stay in the multimodal EON group was 8 days (6, 12) versus 10 days (7, 18) in the conventional care group (P < 0.001). The total cost of treatment and nutritional support were also less in the multi-modal early oral nutrition group (P < 0.001). The effectiveness was 84.9 and 79.9% in the multimodal EON and conventional care group, respectively (P = 0.475). However, the cost-effectiveness ratio was USD 537.6 (506.1, 589.3) and USD 637.8 (593.9, 710.3), respectively (P < 0.001).

Conclusion

The multi-modal early oral nutrition program was an effective way to improve tolerance of oral nutrition during the first week after surgery, decrease the length of stay and improve cost-effectiveness after abdominal surgery.

Trial registration

Registration number: ChiCTR-TRC-14004395. Registered 15 March 2014.

Integrated approach to colorectal anastomotic leakage: Communication, infection and healing disturbances

Colorectal anastomotic leakage (CAL) remains a major complication after colorectal surgery. Despite all efforts during the last decades, the incidence of CAL has not decreased. In this review, we summarize the available strategies regarding prevention, prediction and intervention of CAL and categorize them into three categories: communication, infection and healing disturbances. These three major factors actively interact during the onset of CAL. We aim to provide an integrated approach to CAL based on its etiology. The intraoperative air leak test, intraoperative endoscopy, radiological examinations and stoma construction mainly aim to detect and to prevent communication between the intra- and extra-luminal content. Other strategies including postoperative drainage, antibiotics, and infectious-parameter evaluation are intended to detect and prevent anastomotic or peritoneal infection. Most currently available interventions for CAL focus on the control of communication and infection, while strategies targeting the healing disturbances such as lifestyle changes, oxygen therapy and evaluation of metabolic biomarkers still lack wide clinical application. This simplified categorization may contribute to an integrated understanding of CAL. We strongly believe that this integrated approach should be taken into consideration during clinical practice. An integrated approach to CAL could contribute to a better understanding of the etiology of CAL and eventually better patient outcome.

Postoperative ileus: in search of an international consensus on definition, diagnosis, and treatment

PURPOSE

Postoperative ileus (POI) is a frequent complication after abdominal surgery; nonetheless, it remains poorly defined. Our aim was to achieve an international consensus among leading colorectal surgeons on definition, prevention, and treatment of POI.

METHODS

Thirty-five experts from five continents participated in a three-round Delphi process. Round 1 contained open-ended questions on POI and postoperative nausea and vomiting (PONV). Round 2 included closed-ended questions. Round 3 measured agreement on a 5-point Likert scale. Consensus was defined when items were rated as agree or strongly agree by at least 70 % of the experts.

RESULTS

Experts reached following consensus: POI is a temporary inhibition (86 %) of gastrointestinal motility after surgical intervention due to non-mechanical causes (89 %) and prevents sufficient oral intake (96 %). Abdominal distension/tenderness are the most relevant clinical signs (71 %). Nasogastric tube placement is not mandatory (78 %) but can be removed without previous clamping (81 %)/gastrointestinal contrast study (100 %). Preventive measures are recommended to decrease the risk of POI (96 %): narcotic sparing analgesia (89 %) and fluid optimization (74 %). Treatment of POI should include stimulation of ambulation (96 %) and stop of opioids (74 %). Total parenteral nutrition is recommended from the 7th day without sufficient oral intake (81 %). There was no consensus on the ranking of POI's symptoms, on the imaging modality of choice for the diagnosis of POI, neither on the difference between POI and PONV.

CONCLUSIONS

This Delphi study achieved consensus on the definition, relevant clinical signs, prevention, treatment, and supportive care of POI. Areas of non-consensus were identified (necessity and modality of radiologic imaging to establish the diagnosis, difference between POI and PONV), giving opportunity for further research.

SmartPill® as an objective parameter for determination of severity and duration of postoperative ileus: study protocol of a prospective, two-arm, open-label trial (the PIDuSA study)

INTRODUCTION

Postoperative ileus (POI) is a frequent complication after abdominal surgery (AS). Until today, neither a prophylaxis nor an evidence-based therapy exists. This originates from the absence of objective parameters evaluating the severity and duration of POI resulting in clinical trials of modest quality. The SmartPill(®), a capsule which frequently measures pH value, temperature and intraluminal pressure after swallowing, offers an elegant option for analysing gastrointestinal (GI) transit times and smooth muscle activity in vivo. As the use in patients in the first months after AS is not covered by the marketing authorisation, we aim to investigate the safety and feasibility of the SmartPill(®) immediately after surgery. Additionally, we analyse the influence of prokinetics and laxatives as well as standardised physiotherapy on postoperative bowel contractility, as scientific evidence of its effects is still lacking.

METHODS AND ANALYSIS

The PIDuSA study is a prospective, single-centre, two-arm, open-label trial. The SmartPill(®) will be applied to 55 patients undergoing AS having a high risk for POI and 10 patients undergoing extra-abdominal surgery rarely developing POI. The primary objective is the safety of the SmartPill(®) in patients after surgery on the basis of adverse device effects/serious adverse device effects (ADE/SADE). The sample size suggests that events with a probability of 3% could be seen with a certainty of 80% for at least once in the sample. Secondary objective is the analysis of postoperative intestinal activity in the GI tract in both groups. Furthermore, clinical signs of bowel motility disorders will be correlated to the data measured by the SmartPill(®) to evaluate its significance as an objective parameter for assessing POI severity. Additionally, effects of prokinetics, laxatives and physiotherapy on postoperative peristaltic activity recorded by the SmartPill(®) will be analysed.

ETHICS AND DISSEMINATION

The protocol was approved by the federal authority (94.1.05-5660-8976) and the local ethics committee (092/14-MPG). Findings will be disseminated through publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT02329912; Pre-results.

Establishing a biomarker for postoperative ileus in humans - Results of the BiPOI trial

AIMS

Postoperative ileus (POI) is a frequent complication after abdominal surgery, resulting from an inflammation of the muscularis externa (ME). So far no valid biomarker for occurrence, duration or intensity of POI exists. Extravasation of monocytes and neutrophils from blood circulating into the postoperative ME is well known as a hallmark of POI. In a previous study we demonstrated that a low abundant subset of TH1 cells, activated by IL-12, can be detected in the peripheral blood of a small subset of patients in response to abdominal surgery. The aim of the present study was to investigate if these specific TH1 cells, IL-12 or circulating leukocyte levels could act as a valid marker for POI occurrence.

MAIN METHODS

At different time points, blood samples of patients undergoing abdominal or extraabdominal surgery were collected. Serum levels of IL-12 or TH1 cells as well as neutrophils and monocytes were analyzed. Data were compared between both groups and correlated with clinical signs of POI.

KEY FINDINGS

Time until first flatus and defecation as well as solid food tolerances are delayed after abdominal compared to extraabdominal surgery. Circulating IL-12 levels and numbers of TH1 cells, neutrophils and monocytes did not differ between both groups.

SIGNIFICANCE

While previous experiments indicated that specific TH1 cells play a crucial role in POI dissemination, our present data from a larger human cohort demonstrate that they do not seem to be suitable to distinguish between abdominal and extraabdominal surgery. Furthermore neither TH1 cells nor leukocytes or serum IL-12 levels are appropriate biomarkers for POI in a clinical setting.

Patterns of Brain Activation and Meal Reduction Induced by Abdominal Surgery in Mice and Modulation by Rikkunshito

Abdominal surgery inhibits food intake and induces c-Fos expression in the hypothalamic and medullary nuclei in rats. Rikkunshito (RKT), a Kampo medicine improves anorexia. We assessed the alterations in meal microstructure and c-Fos expression in brain nuclei induced by abdominal surgery and the modulation by RKT in mice. RKT or vehicle was gavaged daily for 1 week. On day 8 mice had no access to food for 6–7 h and were treated twice with RKT or vehicle. Abdominal surgery (laparotomy-cecum palpation) was performed 1–2 h before the dark phase. The food intake and meal structures were monitored using an automated monitoring system for mice. Brain sections were processed for c-Fos immunoreactivity (ir) 2-h after abdominal surgery. Abdominal surgery significantly reduced bouts, meal frequency, size and duration, and time spent on meals, and increased inter-meal interval and satiety ratio resulting in 92–86% suppression of food intake at 2–24 h post-surgery compared with control group (no surgery). RKT significantly increased bouts, meal duration and the cumulative 12-h food intake by 11%. Abdominal surgery increased c-Fos in the prelimbic, cingulate and insular cortexes, and autonomic nuclei, such as the bed nucleus of the stria terminalis, central amygdala, hypothalamic supraoptic (SON), paraventricular and arcuate nuclei, Edinger-Westphal nucleus (E-W), lateral periaqueduct gray (PAG), lateral parabrachial nucleus, locus coeruleus, ventrolateral medulla and nucleus tractus solitarius (NTS). RKT induced a small increase in c-Fos-ir neurons in the SON and E-W of control mice, and in mice with surgery there was an increase in the lateral PAG and a decrease in the NTS. These findings indicate that abdominal surgery inhibits food intake by increasing both satiation (meal duration) and satiety (meal interval) and activates brain circuits involved in pain, feeding behavior and stress that may underlie the alterations of meal pattern and food intake inhibition. RKT improves food consumption post-surgically that may involve modulation of pain pathway.