Establishing core outcome sets for gastrointestinal recovery in studies of postoperative ileus and small bowel obstruction: protocol for a nested methodological study

Development of a core descriptor set for parastomal hernia repair

AIM

Parastomal hernia repair is a poorly evidenced area, with uncertainty around the optimum management. There is considerable heterogeneity within the patient cohort, and currently there is no standardization of patient descriptors in the reporting of parastomal hernia repair. The aim of this study was to develop a core descriptor set of key patient characteristics for patients undergoing surgical repair of a parastomal hernia for reporting in all parastomal hernia research.

METHOD

A longlist of descriptors was generated from a review of the existing literature. The longlist was discussed with patients with lived experience of parastomal hernia repair. Colorectal, general and hernia surgeons took part in a three-round international modified Delphi process using a nine-point Likert scale to rank the importance of descriptors. Items meeting predetermined thresholds were included in the final set and discussed and ratified at the consensus meeting.

RESULTS

Seventy seven respondents completed round one, with 23 (29.8%) completing round three. Eighty six descriptors were rated across the three rounds, with 52 descriptors shortlisted. The consensus meeting ratified a final core descriptor set with 19 descriptors across eight domains: anatomy, contamination, disease, previous treatment, risk factors, symptoms, pathway and other hernia.

CONCLUSION

The core descriptor set reflects characteristics that are important to surgeons when reporting on parastomal hernia repair. The use of this agreed core descriptor set may aid the reporting of future studies.

Pharmacologic prevention and therapy of postoperative paralytic ileus after gastrointestinal cancer surgery: systematic review and meta-analysis

BACKGROUND

Postoperative paralytic ileus (POI) is a significant concern following gastrointestinal tumor surgery. Effective preventive and therapeutic strategies are crucial but remain elusive. Current evidence from randomized-controlled trials on pharmacological interventions for prevention or treatment of POI are systematically reviewed to guide clinical practice and future research.

MATERIALS AND METHODS

Literature was systematically searched for prospective randomized-controlled trials testing pharmacological interventions for prevention or treatment of POI after gastrointestinal tumor surgery. Meta-analysis was performed using a random effects model to determine risk ratios and mean differences with 95% CI. Risk of bias and evidence quality were assessed.

RESULTS

Results from 55 studies, involving 5078 patients who received experimental interventions, indicate that approaches of opioid-sparing analgesia, peripheral opioid antagonism, reduction of sympathetic hyperreactivity, and early use of laxatives effectively prevent POI. Perioperative oral Alvimopan or intravenous administration of Lidocaine or Dexmedetomidine, while safe regarding cardio-pulmonary complications, demonstrated effectiveness concerning various aspects of postoperative bowel recovery [Lidocaine: -5.97 (-7.20 to -4.74)h, P <0.0001; Dexmedetomidine: -13.00 (-24.87 to -1.14)h, P =0.03 for time to first defecation; Alvimopan: -15.33 (-21.22 to -9.44)h, P <0.0001 for time to GI-2 ] and length of hospitalization [Lidocaine: -0.67 (-1.24 to -0.09)d, P =0.02; Dexmedetomidine: -1.28 (-1.96 to -0.60)d, P =0.0002; Alvimopan: -0.58 (-0.84 to -0.32)d, P <0.0001] across wide ranges of evidence quality. Perioperative nonopioid analgesic use showed efficacy concerning bowel recovery as well as length of hospitalization [-1.29 (-1.95 to -0.62)d, P =0.0001]. Laxatives showed efficacy regarding bowel movements, but not food tolerance and hospitalization. Evidence supporting pharmacological treatment for clinically evident POI is limited. Results from one single study suggest that Neostigmine reduces time to flatus and accelerates bowel movements [-37.06 (-40.26 to -33.87)h, P <0.0001 and -42.97 (-47.60 to -38.35)h, P <0.0001, respectively] with low evidence quality.

CONCLUSION

Current evidence concerning pharmacological prevention and treatment of POI following gastrointestinal tumor surgery is limited. Opioid-sparing concepts, reduction of sympathetic hyperreactivity, and laxatives should be implemented into multimodal perioperative approaches.

Postoperative ileus after digestive surgery: Network meta-analysis of pharmacological intervention

AIMS

Several medicinal treatments for avoiding postoperative ileus (POI) after abdominal surgery have been evaluated in randomized controlled trials (RCTs). This network meta-analysis aimed to explore the relative effectiveness of these different treatments on ileus outcome measures.

METHODS

A systematic literature review was performed to identify RCTs comparing treatments for POI following abdominal surgery. A Bayesian network meta-analysis was performed. Direct and indirect comparisons of all regimens were simultaneously compared using random-effects network meta-analysis.

RESULTS

A total of 38 RCTs were included in this network meta-analysis reporting on 6371 patients. Our network meta-analysis shows that prokinetics significantly reduce the duration of first gas (mean difference [MD] = 16 h; credible interval -30, -3.1; surface under the cumulative ranking curve [SUCRA] 0.418), duration of first bowel movements (MD = 25 h; credible interval -39, -11; SUCRA 0.25) and duration of postoperative hospitalization (MD -1.9 h; credible interval -3.8, -0.040; SUCRA 0.34). Opioid antagonists are the only treatment that significantly improve the duration of food recovery (MD -19 h; credible interval -26, -14; SUCRA 0.163).

CONCLUSION

Based on our meta-analysis, the 2 most consistent pharmacological treatments able to effectively reduce POI after abdominal surgery are prokinetics and opioid antagonists. The absence of clear superiority of 1 treatment over another highlights the limits of the pharmacological principles available.

Prolonged Ileus after Colorectal Surgery, a Systematic Review

BACKGROUND

The development of prolonged post-operative ileus (POI) remains a significant problem in the general surgical patient population. The aetiology of ileus is poorly understood and management options/preventative measures are currently extremely limited. The pathophysiology leading to a post-operative ileus is relatively poorly understood, and there is no validated method to estimate ileus occurrence or duration. Ileus in the post-operative period commonly occurs following major colorectal surgery and leads to painful abdominal distension, vomiting, nutritional deficit, pneumonia, prolonged hospital stays and susceptibility to hospital-acquired infection. An increased hospital stay, the burden of treatment costs and the burden on the health system highlight the importance of future research on finding definitions, preventions and predictions of ileus.

METHODS

A systematic literature review was performed to identify randomized controlled trials (RCTs) comparing the rate of ileus on various treatments for prolonged post-operative ileus following colorectal surgery. A confidence evaluation in a meta-analysis were performed using CINeMA. Direct and indirect comparisons of all interventions were simultaneously carried out using a network meta-analysis. The level of certainty was appraised using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. The method of assessing the risk of bias, the quality assessment, used the Cochrane Risk of Bias 2 tool (RoB2).

RESULTS

Among the seven included studies, the majority suffered from considerable within-study bias, affecting the confidence rates of study findings. Heterogeneity and incoherence made the pairwise meta-analysis and ranking of interventions unfeasible. Indirect comparisons were considered unreliable due to this incoherence.

CONCLUSIONS

This systematic review, with a confidence evaluation in the network meta-analysis, determined that there is a knowledge gap in the field of study on prolonged ileus following digestive surgery. The current evidence suffers from heterogeneity and incoherence more than imprecision. There is a gap in the data on ileus occurrence in interventional trials for digestive surgery. This could inform clinicians and trialists to better appraise the current literature and plan future trials.

Patient-Reported Outcomes in Colorectal Surgery

Given the increased life expectancy and improvements in the treatment of colorectal patients, the success of a treatment course can no longer be determined only by objective outcomes. Health care providers ought to take into consideration the impact an intervention will have on the quality of life of patients. Endpoints that take into account the patient's perspective are defined as patient-reported outcomes (PROs). PROs are assessed through patient-reported outcome measures (PROMs), usually in the form of questionnaires. PROs are especially important in colorectal surgery, whose procedures can often be associated with some degree of postoperative functional impairment. Several PROMs are available for colorectal surgery patients. However, while some scientific societies have offered recommendations, there is no standardization in the field and PROMs are seldom implemented in clinical practice. The routine use of validated PROMs can guarantee that functional outcomes are followed over time; this way, they can be addressed in case of worsening. This review will provide an overview of the most commonly used PROMs in colorectal surgery, both generic and disease specific, as well as a summary of the available evidence in support of their routine utilization.

A core outcome set for clinical studies of adhesive small bowel obstruction

AIM

Adhesive small bowel obstruction (ASBO) is a common surgical emergency condition. Research in the field is plentiful; however, inconsistency in outcome reporting makes comparisons challenging. The aim of this study was to define a core outcome set (COS) for studies of ASBO.

METHODS

The long list of outcomes was identified through systematic review, and focus groups across different geographical regions. A modified Delphi consensus exercise of three rounds was undertaken with stakeholder groups (patients and clinicians). Items were rated on a 9-point Likert scale. Items exceeding 70% rating at 7-9 were passed to the consensus meeting. New item proposals were invited in round 1. Individualised feedback on prior voting compared to other participants was provided. An international consensus meeting was convened to ratify the final COS.

RESULTS

In round 1, 56 items were rated by 118 respondents. A total of 18 items reached consensus, and respondents proposed an additional 10 items. Round 2 was completed by 90 respondents, and nine items achieved consensus. In round 3, 80 surveys were completed; one item achieved consensus, and five borderline items were identified. The final COS included 26 outcomes, mapped to the following domains: Interventions, need for stoma, septic complications, return of gut function, patient reported outcomes, and recurrence of obstruction, as well as mortality, failure to rescue, and time to resolution.

CONCLUSION

This COS should be used in future studies in the treatment of adhesive SBO. Further studies to define a core measurement set are needed to identify the optimum tools to measure each outcome.

Relation of gut microbiota and postoperative gastrointestinal dysfunction in older patients with colon cancer undergoing elective colon resection: a protocol for a prospective, observational cohort study

INTRODUCTION

Gut microbiota (GM) appears critical for gastrointestinal symptoms, but whether alterations in GM are associated with increased risk of postoperative gastrointestinal dysfunction (POGID) in older patients with colon cancer (CC) undergoing elective colon resection remains unclear.

METHODS AND ANALYSIS

This study aims to prospectively recruit 284 elderly patients with CC undergoing elective colon resection. GM of fresh faeces specimens is characterised using 16S rRNA gene sequencing. Data are collected preoperatively, daily postoperatively during the in-hospital stay, and follow-up visits are scheduled four times within 30 days after discharge. Associations with POGID will be investigated using logistic regression models to calculate ORs with 95% CIs. The models include the adjustment for age, sex, frequency of spicy diet, coffee drinking and tea drinking, tobacco and alcohol history, diabetes, obesity, gastroenteritis, preoperative gut microbial composition. Furthermore, we will use joint modelling for longitudinal data to study several outcome variables simultaneously.

ETHICS AND DISSEMINATION

This study was approved by the Institutional Review Board of West China Hospital, Sichuan University (IRB Number: 20201334). The results will be disseminated through peer-reviewed publications or conference presentations.

TRIAL REGISTRATION NUMBER

It has been registered in PROSPERO, number CRD42019145032. It has been registered in the Chinese clinical trial registry, number ChiCTR2100043646.

Postoperative Ileus: a Pharmacological Perspective

Post-operative ileus (POI) is a frequent complication after abdominal surgery. The consequences of POI can be potentially serious such as bronchial inhalation or acute functional renal failure. Numerous advances in peri-operative management, particularly early rehabilitation, have made it possible to decrease POI. Despite this, the rate of prolonged POI ileus remains high and can be as high as 25% of patients in colorectal surgery. From a pathophysiological point of view, POI has two phases, an early neurological phase and a later inflammatory phase, to which we could add a "pharmacological" phase during which analgesic drugs, particularly opiates, play a central role. The aim of this review article is to describe the phases of the pathophysiology of POI, to analyse the pharmacological treatments currently available through published clinical trials and finally to discuss the different research areas for potential pharmacological targets.

Gastrointestinal recovery after surgery: protocol for a systematic review

INTRODUCTION

Gastrointestinal recovery after surgery is of worldwide significance. Postoperative gastrointestinal dysfunction is multifaceted and known to represent a major source of postoperative morbidity, however, its significance to postoperative care across all surgical procedures is unknown. The complexity of postoperative gastrointestinal recovery is poorly defined within gastrointestinal surgery, and even less so outside this field. To inform the clinical care of surgical patients worldwide, this systematic review and meta-analysis will aim to characterise the duration of postoperative gastrointestinal recovery that can be expected across all surgical procedures and determine the associations between factors that may affect this.

METHODS AND ANALYSIS

MEDLINE, Embase, Cochrane Library and CINAHL will be searched for studies reporting the time to first postoperative passage of stool after any surgical procedure. We will screen records, extract data and assess risk of bias in duplicate. Forest plots will be constructed for time to postoperative gastrointestinal recovery, as assessed by various outcome measures. Because of potential heterogeneity, a random-effects model will be used throughout the meta-analysis. Funnel plots will be used to test for publication bias. Meta-regressions will be undertaken where the outcome is the mean time to first postoperative passage of stool, with potential predictors and confounders being patient characteristics, postoperative outcomes and surgical factors.

ETHICS AND DISSEMINATION

This study will not involve human or animal subjects and, thus, does not require ethics approval. The outcomes will be disseminated via publication in peer-reviewed scientific journal(s) and presentations at scientific conferences.

PROSPERO REGISTRATION NUMBER

CRD42021256210.

Non-invasive, vagus nerve stimulation to reduce ileus after colorectal surgery: protocol for a feasibility trial with nested mechanistic studies

INTRODUCTION

Ileus is a common and distressing condition characterised by gut dysfunction after surgery. While a number of interventions have aimed to curtail its impact on patients and healthcare systems, ileus is still an unmet challenge. Electrical stimulation of the vagus nerve is a promising new treatment due to its role in modulating the neuro-immune axis through a novel anti-inflammatory reflex. The protocol for a feasibility study of non-invasive vagus nerve stimulation (nVNS), and a programme of mechanistic and qualitative studies, is described.

METHODS AND ANALYSIS

This is a participant-blinded, parallel-group, randomised, sham-controlled feasibility trial (IDEAL Stage 2b) of self-administered nVNS. One hundred forty patients planned for elective, minimally invasive, colorectal surgery will be randomised to four schedules of nVNS before and after surgery. Feasibility outcomes include assessments of recruitment and attrition, adequacy of blinding and compliance to the intervention. Clinical outcomes include bowel function and length of hospital stay. A series of mechanistic substudies exploring the impact of nVNS on inflammation and bowel motility will inform the design of the final stimulation schedule. Semistructured interviews with participants will explore experiences and perceptions of the intervention, while interviews with patients who decline participation will explore barriers to recruitment.

ETHICS AND DISSEMINATION

The protocol has been approved by the Tyne and Wear South National Health Service (NHS) Research Ethics Committee (19/NE/0217) on 2 July 2019. Feasibility, mechanistic and qualitative findings will be disseminated to national and international partners through peer-reviewed publications, academic conferences, social media channels and stakeholder engagement activities. The findings will build a case for or against progression to a definitive randomised assessment as well as informing key elements of study design.

TRIAL REGISTRATION NUMBER

ISRCTN62033341.

Reducing ileus after colorectal surgery: A network meta-analysis of therapeutic interventions

BACKGROUND

Several treatment strategies for avoiding post-operative ileus have been evaluated in randomised controlled trials. This network meta-analysis aimed to explore the relative effectiveness of these different therapeutic interventions on ileus outcome measures.

METHODS

A systematic literature review was performed to identify randomized controlled trials (RCTs) comparing treatments for post-operative ileus following colorectal surgery. A Bayesian network meta-analysis was performed using the Markov chain Monte Carlo method. Direct and indirect comparisons of all regimens were simultaneously compared using random-effects network meta-analysis.

RESULTS

A total of 48 randomised controlled trials were included in this network meta-analysis reporting on 3614 participants. Early feeding was found to be the best treatment for time to solid diet tolerance and length of hospital stay with a probability of P = 0.96 and P = 0.47, respectively. Early feeding resulted in significantly shorter time to solid diet tolerance (Mean Difference (MD) 58.85 h; 95% Credible Interval (CrI) -73.41, -43.15) and shorter length of hospital stay (MD 2.33 days; CrI -3.51, -1.18) compared to no treatment. Epidural analgesia was ranked best treatment for time to flatus (P = 0.29) and time to stool (P = 0.268). Epidural analgesia resulted in significantly shorter time to flatus (MD -18.88 h; CrI -33.67, -3.44) and shorter time to stool (MD -26.05 h; 95% CrI -66.42, 15.65) compared to no intervention. Gastrograffin was ranked best treatment to avoid the requirement for post-operative nasogastric tube insertion (P = 0.61) however demonstrated limited efficacy (OR 0.50; CrI 0.143, 1.621) compared to no intervention. Nasogastric and nasointestinal tube insertion, probiotics, and acupuncture were found to be least efficacious as interventions to reduce ileus.

CONCLUSION

This network meta-analysis identified early feeding as the most efficacious therapeutic intervention to reduce post-operative ileus in patients undergoing colorectal surgery, in addition to highlighting other therapies that require further investigation by high quality study. In patients undergoing colorectal surgery, emphasis should be placed on early feeding as soon as can be appropriately initiated to support the return of gastrointestinal motility.

Impact of STIMUlant and osmotic LAXatives (STIMULAX trial) on gastrointestinal recovery after colorectal surgery: randomized clinical trial

BACKGROUND

Recovery of gastrointestinal (GI) function is often delayed after colorectal surgery. Enhanced recovery protocols (ERPs) recommend routine laxative use, but evidence of benefit is unclear. This study aimed to investigate whether the addition of multimodal laxatives to an ERP improves return of GI function in patients undergoing colorectal surgery.

METHODS

This was a single-centre, parallel, open-label RCT. All adult patients undergoing elective colorectal resection or having stoma formation or reversal at the Royal Adelaide Hospital between August 2018 and May 2020 were recruited into the study. The STIMULAX group received oral Coloxyl® with senna and macrogol, with a sodium phosphate enema in addition for right-sided operations. The control group received standard ERP postoperative care. The primary outcome was GI-2, a validated composite measure defined as the interval from surgery until first passage of stool and tolerance of solid intake for 24 h in the absence of vomiting. Secondary outcomes were the incidence of prolonged postoperative ileus (POI), duration of hospital stay, and postoperative complications. The analysis was performed on an intention-to-treat basis.

RESULTS

Of a total of 170 participants, 85 were randomized to each group. Median GI-2 was 1 day shorter in the STIMULAX compared with the control group (median 2  (i.q.r. 1.5-4) versus 3 (2-5.5) days; 95 per cent c.i. -1 to 0 days; P = 0.029). The incidence of prolonged POI was lower in the STIMULAX group (22 versus 38 per cent; relative risk reduction 42 per cent; P = 0.030). There was no difference in duration of hospital day or 30-day postoperative complications (including anastomotic leak) between the STIMULAX and control groups.

CONCLUSION

Routine postoperative use of multimodal laxatives after elective colorectal surgery results in earlier recovery of gastrointestinal function and reduces the incidence of prolonged POI. Registration number: ACTRN12618001261202 (www.anzctr.org.au).

Noninvasive vagus nerve stimulation to reduce ileus after major colorectal surgery: early development study

AIM

Vagus nerve stimulation has emerged as a plausible intervention to reduce ileus after surgery. An early development study was undertaken with the aim of exploring the feasibility of self-administered, noninvasive vagus nerve stimulation (nVNS) after major colorectal surgery.

METHOD

A parallel-group, randomized controlled trial was undertaken between 1 January 2018 and 31 August 2019. Forty patients undergoing colorectal surgery for malignancy were allocated equally to Sham and Active stimulation groups. Electrical vagus nerve stimulation was self-administered bilaterally over the cervical surface landmarks for 5 days before and after surgery. Outcomes of interest were postoperative complications and adverse events measured using the Clavien-Dindo scale, treatment compliance, device usability according to the Systems Usability Scale (SUS) and clinical measures of bowel recovery.

RESULTS

Forty patients were randomized and one withdrew, leaving 39 for analysis. Postoperative complications occurred in 9/19 (47.4%) participants receiving Sham and 11/20 (55.0%) receiving Active stimulation and were mostly minor. Compliance with treatment before surgery was 4.7 ± 0.9 days out of 5 days in the Sham group and 4.7 ± 1.1 in the Active group. Compliance with treatment after surgery was 4.1 ± 1.1 and 4.4 ± 1.5, respectively. Participants considered the intervention to be 'acceptable' according to the SUS. The most prominent differences in bowel recovery were days to first flatus (2.35 ± 1.32 vs 1.65 ± 0.88) and tolerance of solid diet (2.18 ± 2.21 vs 1.75 ± 0.91) for Sham and Active groups, respectively.

CONCLUSION

This study supports the safety, treatment compliance and usability of self-administered nVNS in patients undergoing major colorectal surgery.

Comparison of treatment to improve gastrointestinal functions after colorectal surgery within enhanced recovery programmes: a systematic review and meta-analysis

Despite a significant improvement with enhanced recovery programmes (ERP), gastro-intestinal (GI) functions that are impaired after colorectal resection and postoperative ileus (POI) remain a significant issue. In the literature, there is little evidence of the distinction between the treatment assessed within or outside ERP. The purpose was to evaluate the efficiency of treatments to reduce POI and improve GI function recovery within ERP. A search was performed in PubMed and Scopus on 20 September 2019. The studies were included if they compared the effect of the administration of a treatment aiming to treat or prevent POI or improve the early functional outcomes of colorectal surgery within an ERP. The main outcome measures were the occurrence of postoperative ileus, time to first flatus and time to first bowel movement. Treatments that were assessed at least three times were included in a meta-analysis. Among the analysed studies, 28 met the eligibility criteria. Six of them focused on chewing-gum and were only randomized controlled trials (RCT) and 8 of them focused on Alvimopan but none of them were RCT. The other measures were assessed in less than 3 studies over RCTs (n = 11) or retrospective studies (n = 2). In the meta-analysis, chewing gum had no significant effect on the endpoints and Alvimopan allowed a significant reduction of the occurrence of POI. Chewing-gum was not effective on GI function recovery in ERP but Alvimopan and the other measures were not sufficiently studies to draw conclusion. Randomised controlled trials are needed.Systematic review registration number CRD42020167339.

Bowel function recovery after laparoscopic transverse colectomy within an ERAS program: a comparison to right and left colectomy

BACKGROUND

It is known that functional recovery of the bowel is slower after right colectomy (RC) compared to left colectomy (LC), but very little has been reported on transverse colectomy (TC).

OBJECTIVES

The aim of this study was to compare the clinical and early functional outcomes of TC, a more infrequent operation, to RC, and LC for colorectal cancer.

METHODS

Between December 2011 and December 2017, all patients undergoing elective colon resection in our institution were treated according to a standardized ERAS protocol and entered in a prospective database. We included in the study patients undergoing laparoscopic TC, RC, or LC for cancer with curative intent. The primary endpoint was prolonged postoperative ileus (PPOI), defined as need to insert a nasogastric tube, or refractory nausea VAS > 4 on or after the third postoperative day. Secondary endpoints were postoperative morbidity and length of hospital stay (LoS).

RESULTS

Out of 286 patients, 126 met the inclusion criteria: 20 underwent TC, 65 RC, and 41 LC. Patients in LC group were younger than in TC and RC groups; other baseline demographics were similar. PPOI was observed in 5 (25%), 26 (40%), and 10 (24%) patients in TC, RC, and LC groups, respectively (p = 0.417). In single group comparisons, the incidence of PPOI in the TC group was significantly lower in comparison to the RC group (OR for RC: 4.255, 95% CI 1.092-16.667, p = 0.037) and similar to the LC group. No significant differences in terms of postoperative complications or LoS stay were observed.

CONCLUSION

The incidence of PPOI after segmental laparoscopic colectomy for cancer within an ERAS program appears as infrequent in TC as in LC and lower than after RC. It may be reasonable to consider a slower oral intake after RC, as it represents an independent predictor of PPOI.

The association of alvimopan treatment with postoperative outcomes after abdominal surgery: A systematic review across different surgical procedures and contexts of perioperative care

BACKGROUND

Alvimopan is a Food and Drug Administration-approved treatment to accelerate gastrointestinal recovery after abdominal surgery; however, benefits may vary across different procedures and contexts of care. The purpose of this study is to summarize the evidence regarding the effect of alvimopan on postoperative outcomes after abdominal surgery.

METHODS

Major databases (Medline, Embase, Biosis, Cochrane, Web of Science, and Scopus) were searched for randomized controlled trials and nonrandomized studies comparing alvimopan versus control. Risk of bias was assessed using Cochrane's risk of bias tool 2.0 (for randomized controlled trials) and Risk of Bias in Nonrandomized Studies-of Intervention tool (for nonrandomized studies). Results were appraised descriptively as heterogeneity in reporting and risk of bias hindered meta-analysis. Quality of evidence across different surgical procedures and contexts of care (ie, open versus minimally invasive surgery, traditional care versus enhanced recovery pathway) was evaluated using Grading of Recommendations Assessment, Development, and Evaluation.

RESULTS

Nine randomized controlled trials and 35 nonrandomized studies were identified. Evidence of low to moderate certainty supports that alvimopan reduces length of stay and improves gastrointestinal recovery after open bowel resection and open radical cystectomy. Limited evidence supports alvimopan for surgeries not listed in Food and Drug Administration labels (ie, total abdominal hysterectomy and retroperitoneal lymph node dissection). Similar effects were observed in traditional and enhanced recovery pathway settings, but enhanced recovery pathway elements varied across studies. There is very low certainty of evidence supporting alvimopan for patients undergoing minimally invasive surgery.

CONCLUSION

Evidence supports that alvimopan improves outcomes after open bowel resection and open radical cystectomy. Benefits for patients undergoing minimally invasive surgery and treated in contemporary enhanced recovery pathway settings remain uncertain. These findings contribute important new knowledge to inform evidence-based alvimopan prescribing.

Changes to gastrointestinal function after surgery for colorectal cancer

Bowel function is increasingly considered as an important outcome for patients undergoing surgery for colorectal cancer. Increasing technical skills and technological advances have meant fewer patients require a long-term stoma but this comes at the cost, often, of poor function. With a larger range of treatment options available for a given cancer, both function and oncology should be considered in parallel when counselling patients before surgery. In the perioperative phase, bowel function can be improved with minimally invasive surgery and enhanced recovery after surgery protocols, with limited evidence for targeted medical therapies. Early detection and sound management of surgical complications such as anastomotic leak and stricture can mitigate their adverse effects on bowel function. Long-term gastrointestinal dysfunction manifests as diarrhoea and low anterior resection syndrome for colon and rectal cancer respectively. Multi-modal strategies for low anterior resection syndrome are emerging to improve significantly quality of life after restorative rectal cancer surgery.