Phase III trial of alvimopan, a novel, peripherally acting, mu opioid antagonist, for postoperative ileus after major abdominal surgery

Alvimopan for postoperative ileus following abdominal surgery: a systematic review

BACKGROUND

Postoperative ileus (POI) is a common complication following abdominal surgery, often leading to extended hospital stays and a higher risk of post-operative complications, leading to poorer patient outcomes. Alvimopan, a peripherally acting µ-opioid receptor antagonist, has been shown to aid in the recovery of normal bowel function after surgery. While its benefits are well-established in open abdominal surgeries, its efficacy in laparoscopic procedures had not been conclusively determined. However, recent clinical trials involving laparoscopic surgeries have since been conducted. This review aims to reassess the efficacy of Alvimopan by incorporating findings from these new studies, potentially providing further insight into its clinical benefits.

METHODS

A comprehensive search of PubMed, Google Scholar, EMBASE, and the Cochrane Library was conducted. Studies were included based on the PICO framework, focusing on Alvimopan's impact on postoperative gastrointestinal recovery. Primary outcomes were time to gastrointestinal function recovery (GI-3) and hospital stay duration.

RESULTS

Ten studies met the inclusion criteria, with seven focusing on the use of Alvimopan in open abdominal surgeries and three in laparoscopic procedures. Collectively, these studies involved 18,822 patients undergoing various types of abdominal Administration of Alvimopan 6 mg accelerated gastrointestinal function recovery by an average of 14 h (Hazard ratio: 1.62, p = 0.002) and reduced hospital stays by 5.2 h (Hazard ratio: 1.52, p = 0.04) compared to placebo. Similarly, Alvimopan 12 mg reduced GI-3 recovery time by 13.5 h (Hazard ratio: 1.58, p = 0.02) and hospital stay duration by 6.2 h (Hazard ratio: 1.46, p = 0.018).

CONCLUSION

Alvimopan shows promise in reducing POI and hospital stay durations following abdominal surgeries. The incorporation of the recent studies in laparoscopic abdominal procedures further supports these findings. Integrating Alvimopan into perioperative care protocols may enhance patient outcomes and help lower healthcare costs.

Early versus delayed oral feeding after major gynaecologic surgery

BACKGROUND

This is an updated and expanded version of the original Cochrane review, first published in 2014. Postoperative oral intake is traditionally withheld after major abdominal gynaecologic surgery until the return of bowel function. The concern is that early oral intake will result in vomiting and severe paralytic ileus, with subsequent aspiration pneumonia, wound dehiscence, and anastomotic leakage. However, clinical studies suggest that there may be benefits from early postoperative oral intake. Currently, gynaecologic surgery can be performed through various routes: open abdominal, vaginal, laparoscopic, robotic, or a combination. In this version, we included women undergoing major gynaecologic surgery through all of these routes, either alone or in combination.

OBJECTIVES

To assess the effects of early versus delayed (traditional) initiation of oral intake of food and fluids after major gynaecologic surgery.

SEARCH METHODS

On 13 June 2023, we searched the Cochrane Gynaecology and Fertility Group's Specialised Register, CENTRAL, MEDLINE, Embase, the citation lists of relevant publications, and two trial registries. We also contacted experts in the field for any additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared the effect of early versus delayed initiation of oral intake of food and fluids after major gynaecologic surgery, performed by abdominal, vaginal, laparoscopic, and robotic approaches. Early feeding was defined as oral intake of fluids or food within 24 hours post-surgery, regardless of the return of bowel function. Delayed feeding was defined as oral intake after 24 hours post-surgery, and only after signs of postoperative ileus resolution. Primary outcomes were: postoperative ileus, nausea, vomiting, cramping, abdominal pain, bloating, abdominal distension, need for postoperative nasogastric tube, time to the presence of bowel sounds, time to the first passage of flatus, time to the first passage of stool, time to the start of a regular diet, and length of postoperative hospital stay. Secondary outcomes were: infectious complications, wound complications, deep venous thrombosis, urinary tract infection, pneumonia, satisfaction, and quality of life.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed the risk of bias, and extracted the data. We calculated the risk ratio (RR) with a 95% confidence interval (CI) for dichotomous data. We examined continuous data using the mean difference (MD) and a 95% CI. We tested for heterogeneity between the results of different studies using a forest plot of the meta-analysis, the statistical tests of homogeneity of 2 x 2 tables, and the I² value. We assessed the certainty of the evidence using GRADE methods.

MAIN RESULTS

We included seven randomised controlled trials (RCTs), randomising 902 women. We are uncertain whether early feeding compared to delayed feeding has an effect on postoperative ileus (RR 0.49, 95% CI 0.21 to 1.16; I² = 0%; 4 studies, 418 women; low-certainty evidence). We are uncertain whether early feeding affects nausea or vomiting, or both (RR 0.94, 95% CI 0.66 to 1.33; I² = 67%; random-effects model; 6 studies, 742 women; very low-certainty evidence); nausea (RR 1.24, 95% CI 0.51 to 3.03; I² = 74%; 3 studies, 453 women; low-certainty evidence); vomiting (RR 0.83, 95% CI 0.52 to 1.32; I² = 0%; 4 studies, 559 women; low-certainty evidence), abdominal distension (RR 0.99, 95% CI 0.75 to 1.31; I² = 0%; 4 studies, 559 women; low-certainty evidence); need for postoperative nasogastric tube placement (RR 0.46, 95% CI 0.14 to 1.55; 3 studies, 453 women; low-certainty evidence); or time to the presence of bowel sounds (MD -0.20 days, 95% CI -0.46 to 0.06; I² = 71%; random-effects model; 3 studies, 477 women; low-certainty evidence). There is probably no difference between the two feeding protocols for the onset of flatus (MD -0.11 days, 95% CI -0.23 to 0.02; I² = 9%; 5 studies, 702 women; moderate-certainty evidence). Early feeding probably results in a slight reduction in the time to the first passage of stool (MD -0.18 days, 95% CI -0.33 to -0.04; I² = 0%; 4 studies, 507 women; moderate-certainty evidence), and may lead to a slightly sooner resumption of a solid diet (MD -1.10 days, 95% CI -1.79 to -0.41; I² = 97%; random-effects model; 3 studies, 420 women; low-certainty evidence). Hospital stay may be slightly shorter in the early feeding group (MD -0.66 days, 95% CI -1.17 to -0.15; I² = 77%; random-effects model; 5 studies, 603 women; low-certainty evidence). The effect of the two feeding protocols on febrile morbidity is uncertain (RR 0.96, 95% CI 0.75 to 1.22; I² = 47%; 3 studies, 453 women; low-certainty evidence). However, infectious complications are probably less common in women with early feeding (RR 0.20, 95% CI 0.05 to 0.73; I² = 0%; 2 studies, 183 women; moderate-certainty evidence). There may be no difference between the two feeding protocols for wound complications (RR 0.82, 95% CI 0.50 to 1.35; I² = 0%; 4 studies, 474 women; low-certainty evidence), or pneumonia (RR 0.35, 95% CI 0.07 to 1.73; I² = 0%; 3 studies, 434 women; low-certainty evidence). Two studies measured participant satisfaction and quality of life. One study found satisfaction was probably higher in the early feeding group, while the other study found no difference. Neither study found a significant difference between the groups for quality of life (P > 0.05).

AUTHORS' CONCLUSIONS

Despite some uncertainty, there is no evidence to indicate harmful effects of early feeding following major gynaecologic surgery, measured as postoperative ileus, nausea, vomiting, or abdominal distension. The potential benefits of early feeding include a slightly faster initiation of bowel movements, a slightly sooner resumption of a solid diet, a slightly shorter hospital stay, a lower rate of infectious complications, and a higher level of satisfaction.

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.

Strategies to reduce ileus after colorectal surgery: A qualitative umbrella review of the collective evidence

BACKGROUND

Various strategies were proposed to reduce postoperative ileus after colorectal surgery. This umbrella review aimed to provide a comprehensive overview of current evidence on measures to reduce the incidence and severity of postoperative ileus after colorectal surgery.

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic search was conducted in PubMed and Scopus to identify systematic reviews that assessed the efficacy of interventions used to prevent postoperative ileus after colorectal surgery. Data on study characteristics, interventions, and outcomes were summarized in a narrative manner.

RESULTS

A total of 26 systematic reviews incorporating various strategies like early oral feeding, gum chewing, coffee consumption, medications, and acupuncture were included. Early oral feeding reduced postoperative ileus and accelerated bowel function return. The most assessed intervention was chewing gum, which was associated with a median reduction of postoperative ileus by 45% (range, 11%-59%) and shortening of the time to first flatus and time to defecation by a median of 11.9 and 17.7 hours, respectively. Coffee intake showed inconsistent results, with a median shortening of time to flatus and time to defecation by 1.32 and 14.45 hours, respectively.

CONCLUSION

Early oral feeding, chewing gum, and alvimopan were the most commonly assessed and effective strategies for reducing postoperative ileus after colorectal surgery. Medications used to reduce postoperative ileus included alvimopan, intravenous lidocaine, dexamethasone, probiotics, and oral antibiotics. Intravenous dexamethasone and lidocaine and oral probiotics helped hasten bowel function return. Acupuncture positively impacted the recovery of bowel function.

Alvimopan is associated with favorable outcomes in open and minimally invasive colorectal surgery: a regional database analysis

BACKGROUND

Alvimopan is a µ-opioid receptor antagonist associated with shorter time to gastrointestinal recovery in patients having open colorectal surgery. Data demonstrating the benefit of perioperative alvimopan for the minimally invasive surgical approach are inconsistent. The aim of this study is to determine colorectal surgery groups that benefit from perioperative alvimopan.

METHODS

This is a retrospective cohort analysis of colorectal surgery patients who had, and patients who did not have, perioperative alvimopan in the Michigan Surgical Quality Collaborative regional risk-adjusted database from 2018 through 2021. Main outcome measures were postoperative length of hospital stay, time to return of bowel function, and postoperative ileus.

RESULTS

There were 10,010 patients (30.3% open, 40.5% laparoscopic, 12.7% hand-assist laparoscopic, 43.5% robotic) who met inclusion criteria-4919 received alvimopan in the perioperative period and 5091 did not. When compared to those not receiving alvimopan, unadjusted outcomes showed that the alvimopan group had significantly shorter postoperative length of stay (4.75 days vs 5.5 days, p < 0.001), shorter time to return of bowel function (1.61 days vs 2.01 days, p < 0.001) and less postoperative ileus (5.45% vs 7.94%, p < 0.001). After adjustment, regression models confirmed that alvimopan was associated with an 9.6% reduction in hospital length of stay (p < 0.001), a 14.9% shorter time to return of bowel function (p < 0.001), and a 42.1% reduction in postoperative ileus (p < 0.001). Subgroup analysis showed significant benefit of alvimopan for all three outcomes in patients having the minimally invasive approach.

CONCLUSIONS

Alvimopan is associated with shorter hospital length of stay, shorter time to return of bowel function, and decreased postoperative ileus when administered to patients undergoing colorectal surgery. Benefit is not limited to the open approach and includes minimally invasive laparoscopic and robotic colorectal procedures.

Clinical practice guidelines for enhanced recovery after colon and rectal surgery from the American Society of Colon and Rectal Surgeons and the Society of American Gastrointestinal and Endoscopic Surgeons

The American Society of Colon and Rectal Surgeons (ASCRS) and the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) are dedicated to ensuring high-quality innovative patient care for surgical patients by advancing the science, prevention, and management of disorders and diseases of the colon, rectum, and anus as well as minimally invasive surgery. The ASCRS and SAGES society members involved in the creation of these guidelines were chosen because they have demonstrated expertise in the specialty of colon and rectal surgery and enhanced recovery. This consensus document was created to lead international efforts in defining quality care for conditions related to the colon, rectum, and anus and develop clinical practice guidelines based on the best available evidence. While not proscriptive, these guidelines provide information on which decisions can be made and do not dictate a specific form of treatment. These guidelines are intended for the use of all practitioners, healthcare workers, and patients who desire information about the management of the conditions addressed by the topics covered in these guidelines. These guidelines should not be deemed inclusive of all proper methods of care nor exclusive of methods of care reasonably directed toward obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all the circumstances presented by the individual patient. This clinical practice guideline represents a collaborative effort between the American Society of Colon and Rectal Surgeons (ASCRS) and the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) and was approved by both societies.

Alvimopan for the reduction of postoperative ileus after long posterior spinal fusion: placebo-controlled double-blind randomized trial

OBJECTIVE

The aim of this study was to evaluate the efficacy of alvimopan administration after posterior spinal fusion (PSF) in adult spine surgery patients who are taking opioid agents.

METHODS

In this placebo-controlled, double-blind randomized trial, PSF patients were randomized in blocks to placebo or study drug. Primary and secondary outcome measures were return to normal bowel function, including time to passage of flatus and stool, time to tolerance of oral nutrition, and time to hospital discharge. Patients were included regardless of chronic opioid consumption status.

RESULTS

Thirty-one patients provided consent for participation, and 26 patients (13 per group) completed the study. There were no differences between groups with respect to time to flatus, time to bowel movement, time to oral nutrition tolerance, and time to discharge. Calculated effect sizes favored placebo for all interventions.

CONCLUSIONS

Alvimopan did not hasten return to bowel function for any primary or secondary outcome measures when compared with placebo for patients undergoing PSF. There were no adverse events related to alvimopan, including for patients with chronic opioid consumption. While underpowered to determine a statistical difference, it is unlikely that a clinically relevant effect exists.

The Problem of Appetite Loss After Major Abdominal Surgery

Objective:

To systematically review the problem of appetite loss after major abdominal surgery.

Summary of Background Data:

Appetite loss is a common problem after major abdominal surgery. Understanding of etiology and treatment options is limited.

Methods:

We searched Medline, Cochrane Central Register of Controlled Trials, and Web of Science for studies describing postoperative appetite loss. Data were extracted to clarify definition, etiology, measurement, surgical influence, pharmacological, and nonpharmacological treatment. PROSPERO registration ID: CRD42021224489.

Results:

Out of 6144 articles, we included 165 studies, 121 of which were also analyzed quantitatively. A total of 19.8% were randomized, controlled trials (n = 24) and 80.2% were nonrandomized studies (n = 97). The studies included 20,506 patients undergoing the following surgeries: esophageal (n = 33 studies), gastric (n = 48), small bowel (n = 6), colon (n = 27), rectal (n = 20), hepatobiliary (n = 6), and pancreatic (n = 13). Appetite was mostly measured with the Quality of Life Questionnaire of the European Organization for Research and Treatment of Cancer (EORTC QLQ C30, n = 54). In a meta-analysis of 4 randomized controlled trials gum chewing reduced time to first hunger by 21.2 hours among patients who had bowel surgery. Other reported treatment options with positive effects on appetite but lower levels of evidence include, among others, intravenous ghrelin administration, the oral Japanese herbal medicine Rikkunshito, oral mosapride citrate, multidisciplin-ary-counseling, and watching cooking shows. No studies investigated the effect of well-known appetite stimulants such as cannabinoids, steroids, or megestrol acetate on surgical patients.

Conclusions:

Appetite loss after major abdominal surgery is common and associated with increased morbidity and reduced quality of life. Recent studies demonstrate the influence of reduced gastric volume and ghrelin secretion, and increased satiety hormone secretion. There are various treatment options available including level IA evidence for postoperative gum chewing. In the future, surgical trials should include the assessment of appetite loss as a relevant outcome measure.

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.

Alvimopan retains efficacy in patients undergoing colorectal surgery within an established ERAS program

BACKGROUND

Post-operative ileus and delayed return of gastrointestinal function are complications seen frequently in patients undergoing colorectal surgery. Many enhanced recovery after surgery protocols include alvimopan to inhibit the effects of opiates in the gastrointestinal tract and lidocaine to augment analgesics. Limited data exist regarding alvimopan's efficacy in opiate-sparing regimens.

METHODS

This single-center, retrospective cohort analysis was conducted in a randomly selected population of adult patients undergoing colorectal resection between February 2018 and October 2019. Patients meeting inclusion criteria were divided into four groups dependent upon whether or not they received alvimopan (A or a) and/or lidocaine (L or l). The primary endpoint in this study was median time to first bowel movement or discharge, whichever came first. Our secondary endpoint was length of stay.

RESULTS

Of the 430 patients evaluated, a total of 192 patients were included in the final evaluation in the following groups: AL (n = 93), Al (n = 34), aL (n = 44), and al (n = 21). A significant difference was found among the groups for the primary outcome of median time to bowel movement or discharge (p = 0.001). Three subsequent pair-wise comparisons resulted in a significant difference in the primary outcome: group AL 39.4 h vs. group aL 54.0 h (p = 0.003), group AL 39.4 h vs. group al 55.4 h (p = 0.001), and group Al 44.9 h vs. group al 55.4 h (p = 0.01). Length of stay was significantly reduced by 1.8 days in groups AL and Al compared to group aL (p < 0.001).

CONCLUSION

Treatment with alvimopan resulted in a significant improvement in time to GI recovery and decreased length of stay in an established ERAS program. While lidocaine's reduction in opiates was minimal, the group receiving both alvimopan and lidocaine had the greatest reduction in time to GI recovery and length of stay.

Updates on enhanced recovery after surgery for radical cystectomy

Enhanced Recovery after Surgery (ERAS) is a multimodal pathway that provides evidence-based guidance for improving perioperative care and outcomes in patients undergoing surgery. In 2013, the ERAS society released its original guidelines for radical cystectomy (RC) for bladder cancer (BC), adopting much of its supporting data from colorectal literature. In the last decade, growing interest in ERAS has increased RC-specific ERAS research, including prospective randomized controlled trials (RCTs). Collective data suggest ERAS contributes to improved complication rates, decreased hospital length-of-stay, and/or time to bowel recovery. Various institutions have adopted modified versions of the ERAS pathway, yet there remains a lack of consensus on the efficacy of specific ERAS items and standardization of the protocol. In this review, we summarize updated evidence and practice patterns of ERAS pathways for RC since the introduction of the original 2013 guidelines. Novel target interventions, including use of immunonutrition, prehabilitation, alvimopan, and methods of local analgesia are reviewed. Finally, we discuss barriers to implementing and future steps in advancing the ERAS movement.

Design and feasibility of a double-blind, randomized trial of peri-operative methylnaltrexone for postoperative ileus prevention after adult spinal arthrodesis

BACKGROUND

Postoperative ileus (POI) is a common complication with no proven prophylactic measures in place. While perioperative opioid use has been implicated in POI development, current treatments fail to target this disease mechanism. Methylnaltrexone (MNTX) has been used to prevent the effects of opioids on the bowel and could reduce the incidence of POI when administered preoperatively.

METHODS

In this phase IIb randomized controlled trial, we assessed the effect of perioperative MNTX on time-to-first-bowel movement following spinal arthrodesis surgeries.

RESULTS

82 patients were randomly selected in a 1:1 ratio to be included in either the treatment or placebo groups. Comparison of relevant factors of included patients to patients who refused to participate (n = 21) and to a prior retrospective series (n = 241) revealed no differences in age, male sex, liver disease, and number of surgical levels. Overall treatment fidelity (98% adherence) and retention (100% at one-month follow-up) were high. The predicted POI incidence (9.3-11.1%) was also equivalent to a prior retrospective series. However, the overall observed POI incidence (3.7%) was lower than expected, which could reflect a superimposed 'trial effect' related to standardized care in a research setting.

CONCLUSIONS

Since exposure to significant opioid doses represents a barrier to enhanced recovery after surgery, the results of this innovative trial may provide further guidance for the peri-operative use of opioid-receptor blockers. Here, we show that MNTX can be effectively administered in the peri-operative period with appropriate follow-up achieved in a representative population of patients undergoing spinal surgery.

TRIAL REGISTRATION NUMBERS

Clinicaltrials.gov - NCT03852524 and Institutional Review Board - 2018H0260.

Dissecting the Perioperative Care Bundle

Enhanced recovery after surgery (ERAS) protocols are comprehensive perioperative care pathways designed to mitigate the physiologic stressors associated with surgery and, in turn, improve clinical outcomes and lead to health care cost savings. Although individual components may differ, ERAS protocols are typically organized as multimodal care "bundles" that, when followed closely and in their entirety, are meant to generate amplified cumulative benefits. This manuscript examines some of the critical components, describes some areas where the science is weak (but dogma may be strong), and provides some of the evidence or lack thereof behind components of a standard ERAS protocol.

Postoperative ileus-An ongoing conundrum

BACKGROUND

Postoperative ileus is common and is a major clinical problem. It has been widely studied in patients and in experimental models in laboratory animals. A wide variety of treatments have been tested to prevent or modify the course of this disorder.

PURPOSE

This review draws together information on animal studies of ileus with studies on human patients. It summarizes some of the conceptual advances made in understanding the mechanisms that underlie paralytic ileus. The treatments that have been tested in human subjects (both pharmacological and non-pharmacological) and their efficacy are summarized and graded consistent with current clinical guidelines. The review is not intended to provide a comprehensive overview of ileus, but rather a general understanding of the major clinical problems associated with it, how animal models have been useful to elucidate key mechanisms and, finally, some perspectives from both scientists and clinicians as to how we may move forward with this debilitating yet common condition.

Peripherally Acting μ-Opioid Receptor Antagonists in the Management of Postoperative Ileus: a Clinical Review

Postoperative ileus (POI) and constipation are common secondary effects of opioids and carry significant clinical and economic impacts. μ-Opioid receptors mediate opioid analgesia in the central nervous system (CNS) and gastrointestinal-related effects in the periphery. Peripherally acting μ-opioid receptor antagonists (PAMORAs) block the peripheral effects of opioids in the gastrointestinal tract, while maintaining opioid analgesia in the CNS. While most are not approved for POI or postoperative opioid-induced constipation (OIC), PAMORAs have a potential role in these settings via their selective effects on the μ-opioid receptor. This review will discuss recent clinical trials evaluating the safety and efficacy of PAMORAs, with a focus on alvimopan (Entereg^®) and methylnaltrexone (Relistor^®) in patients with POI or postoperative OIC. We will characterize potential factors that may have impacted the efficacy observed in phase 3 trials and discuss future directions for the management and treatment of POI.

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.

Alvimopan is associated with decreased length of stay for both open and laparoscopic segmental colectomy

BACKGROUND

Alvimopan has been shown to reduce length of stay after bowel resection. Use remains variable among institutions due to cost and efficacy concerns in laparoscopic surgery. Additionally, alvimopan's effects have not been isolated from other medications within enhanced recovery protocols. The aim of this study was to distinguish the relationship between alvimopan use, length of stay, and cost in both open and laparoscopic segmental colectomies.

METHODS

The Vizient dataset was queried to identify patients undergoing open and laparoscopic colectomies from 2015 to 2017. Patient demographics and treatment details were collected. Primary outcomes of interest included duration of stay and total direct costs.

RESULTS

In the study, 12,727 patients met inclusion criteria and 3,358 (26.4%) received alvimopan. For both open and laparoscopic groups, alvimopan was associated with decreased length of stay in unadjusted (4.0 vs 6.0 days, P < .01 and 3.0 vs 4.0 days, P < .01, respectively) and adjusted analysis (effect ratio 0.79, P < .01 and 0.85, P < .01, respectively). Alvimopan was associated with a 7% decrease in direct cost after adjustment (effect ratio 0.93, P = .04), with no cost difference in laparoscopic procedures (effect ratio 0.99, P = .71).

CONCLUSION

Alvimopan use is associated with decreased length of stay for both open and laparoscopic colon resections, decreased cost in open procedures, and no cost difference for laparoscopic procedures.

Canadian consensus statement: enhanced recovery after surgery in bariatric surgery

BACKGROUND

In Canada, bariatric surgery continues to remain the most effective treatment for severe obesity and its comorbidities. As the number of bariatric surgeries continues to grow, the need for consensus guidelines for optimal perioperative care is imperative. In colorectal surgery, enhanced recovery after surgery (ERAS) protocols were created for this purpose. The objective of this review is to develop evidence-based ERAS guidelines for bariatric surgery.

METHODS

A literature search of the MEDLINE database was performed using ERAS-specific search terms. Recently published articles with a focus on randomized controlled trials, systematic reviews, and meta-analyses were included. Quality of evidence and recommendations were evaluated using the GRADE assessment system.

RESULTS

Canadian bariatric surgeons from six provinces and ten bariatric centers performed a review of the evidence surrounding ERAS in bariatric surgery and created consensus guidelines for 14 essential ERAS elements. Our main recommendations were (1) to encourage participation in a presurgical weight loss program; (2) to abstain from tobacco and excessive alcohol; (3) low-calorie liquid diet for at least 2 weeks prior to surgery; (4) to avoid preanesthetic anxiolytics and long-acting opioids; (5) unfractionated or low-molecular-weight heparin prior to surgery; (6) antibiotic prophylaxis with cefazolin ± metronidazole; (7) reduced opioids during surgery; (8) surgeon preference regarding intraoperative leak testing; (9) nasogastric intubation needed only for Veress access; (10) to avoid abdominal drains and urinary catheters; (11) to prevent ileus by discontinuing intravenous fluids early; (12) postoperative analgesia with acetaminophen, short-term NSAIDS, and minimal opioids; (13) to resume full fluid diet on first postoperative day; (14) early telephone follow-up with full clinic follow-up at 3-4 weeks.

CONCLUSIONS

The purpose of addressing these ERAS elements is to develop guidelines that can be implemented and practiced clinically. ERAS is an excellent model that improves surgical efficiency and acts as a common perioperative pathway. In the interim, this multimodal bariatric perioperative guideline serves as a common consensus point for Canadian bariatric surgeons.

Alvimopan Significantly Reduces Length of Stay and Costs Following Colorectal Resection and Ostomy Reversal Even Within an Enhanced Recovery Protocol

BACKGROUND

Alvimopan accelerates GI recovery after colorectal resection. Data on real-world cost-effectiveness have been mixed.

OBJECTIVE

This study aimed to evaluate if adding alvimopan to an enhanced recovery pathway reduces length of stay.

DESIGN

Patients undergoing colorectal resection or ostomy reversal for the year before and after the introduction of alvimopan were evaluated.

SETTING

This study was conducted at a single academic medical center.

PATIENTS

Patients undergoing elective colorectal resection (488) or ostomy reversal (148) were included.

MAIN OUTCOME MEASURES

The primary outcomes measured were length of stay and prolonged length of stay defined as >75th percentile for each procedure.

RESULTS

Two hundred eighty-six patients (45%) received alvimopan. Alvimopan and no-alvimopan groups had similar demographics, comorbidities, operative indication, and case mix. In the alvimopan group, more of the colorectal resections were laparoscopic (87% vs 79%, p = 0.015). Length of stay was reduced with alvimopan (6.2 vs 4.9 days, p = 0.003), and this effect persisted when controlling for procedure type, approach, and ASA class (decreased length of stay by 1.0 day, p = 0.014). The alvimopan group had lower risk of prolonged length of stay (14.7% vs 23.1%, p = 0.007) and ileus (10.8% vs 16.2%, p = 0.05). On multivariable analysis, no alvimopan use (OR, 1.8; 95% CI, 1.2-2.7), ASA ≥3 (OR, 2.0; 95% CI, 1.3-3.1), and history of cardiac surgery (OR, 2.8; 95% CI, 1.2-6.5) were significant predictors of prolonged length of stay. Alvimopan use was associated with a lower risk of infectious complications other than surgical site infection (2.8% vs 6.7%, p = 0.025), and did not increase risk of any adverse outcomes. The addition of alvimopan to the protocol resulted in cost savings of $708.39 per patient.

LIMITATIONS

Data collected from a single center limit external validity.

CONCLUSIONS

The introduction of alvimopan to a postoperative protocol following elective colorectal resection or ostomy reversal significantly reduces length of stay and is associated with cost savings even within an enhanced recovery protocol. See Video Abstract at http://links.lww.com/DCR/A911.

Surgical Care and Outcomes Assessment Program (SCOAP): A Nuanced, Flexible Platform for Colorectal Surgical Research

The Surgical Care and Outcomes Assessment Program (SCOAP) is a surgeon-led quality improvement (QI) initiative developed in Washington State to track and reduce variability in surgical care. It has developed into a collaboration of over two-thirds of the hospitals in the state, who share data and receive regular benchmarking reports. Data are abstracted at each site by trained abstractors. While there has some overlap with other national QI databases, the data captured by SCOAP has clinical nuances that make it pragmatic for studying surgical care. We review the unique properties of SCOAP and offer some examples of its novel applications.

Meta-analysis of the effect of perioperative intravenous lidocaine on return of gastrointestinal function after colorectal surgery

BACKGROUND

Return of normal gastrointestinal (GI) function is a critical determinant of recovery after colorectal surgery. The aim of this meta-analysis was to evaluate whether perioperative intravenous (IV) lidocaine benefits return of gastrointestinal function after colorectal resection.

METHODS

A comprehensive search of Ovid Medline, PubMed, Embase, Cochrane library, and clinicaltrials.org was performed on 1st July 2018. A manual search of reference lists was also performed. Inclusion criteria were as follows: randomized controlled trials (RCTs) of intravenous (IV) lidocaine administered perioperatively compared to placebo (0.9% saline infusion) as part of a multimodal perioperative analgesic regimen, human adults (> 16 years), and open or laparoscopic colorectal resectional surgery.

EXCLUSION CRITERIA

non-colorectal surgery, non-placebo comparator, children, non-general anaesthetic, and pharmacokinetic studies. The primary endpoint was time to first bowel movement. Secondary endpoints were time to first passage of flatus, time to toleration of diet, nausea and vomiting, ileus, pain scores, opioid analgesia consumption, and length of stay.

RESULTS

One hundred and ninety one studies were screened, with 9 RCTs meeting inclusion criteria (405 patients, four laparoscopic and five open surgery studies). IV lidocaine reduced time to first bowel movement compared to placebo [seven studies, 325 patients, mean weighted difference - 9.54 h, 95% CI 18.72-0.36, p = 0.04]. Ileus, pain scores, and length of stay were reduced with IV lidocaine compared with placebo.

CONCLUSIONS

Perioperative IV lidocaine may improve recovery of gastrointestinal function after colorectal surgery. Large-scale effectiveness studies to measure effect size and evaluate optimum dose/duration are warranted.

Statewide Clinic Registries: The Michigan Surgical Quality Collaborative

Regional clinical registries provide a unique opportunity for shared learning and population-based analyses of the quality of surgical care. Through the "Michigan Model" of pay for participation in strategic Value Partnerships, exemplified by the Michigan Surgical Quality Collaborative (MSQC), the state's dominant private insurer, Blue Cross Blue Shield of Michigan, has sponsored 20 statewide clinical quality improvement collaboratives. MSQC represents a partnership among 73 Michigan hospitals with a robust data infrastructure and flexible platform for the promulgation of best practices in surgical quality improvement. This article will describe the organizational structure of the MSQC, the contributions the registry has made to quality improvement in colorectal surgery, and how future work will align to improve the reliability of improvement-relevant registry data.

Surgical technical evidence review for gynecologic surgery conducted for the Agency for Healthcare Research and Quality Safety Program for Improving Surgical Care and Recovery

BACKGROUND

The Agency for Healthcare Research and Quality, in partnership with the American College of Surgeons and the Armstrong Institute at Johns Hopkins, developed the Safety Program for Improving Surgical Care and Recovery, which integrates principles of implementation science into adoption of enhanced recovery pathways and promotes evidence-based perioperative care.

OBJECTIVE

The objective of this study is to review the enhanced recovery pathways literature in gynecologic surgery and provide the framework for an Improving Surgical Care and Recovery pathway for gynecologic surgery.

STUDY DESIGN

We searched PubMed and Cochrane Central Register of Controlled Trials databases from 1990 through October 2017. Studies were included in hierarchical and chronological order: meta-analyses, systematic reviews, randomized controlled trials, and interventional and observational studies. Enhanced recovery pathways components relevant to gynecologic surgery were identified through review of existing pathways. A PubMed search for each component was performed in gynecologic surgery and expanded to include colorectal surgery as needed to have sufficient evidence to support or deter a process. This review focuses on surgical components; anesthesiology components are reported separately in a companion article in the anesthesiology literature.

RESULTS

Fifteen surgical components were identified: patient education, bowel preparation, elimination of nasogastric tubes, minimization of surgical drains, early postoperative mobilization, early postoperative feeding, early intravenous fluid discontinuation, early removal of urinary catheters, use of laxatives, chewing gum, peripheral mu antagonists, surgical site infection reduction bundle, glucose management, and preoperative and postoperative venous thromboembolism prophylaxis. In addition, 14 components previously identified in the colorectal Improving Surgical Care and Recovery pathway review were included in the final pathway.

CONCLUSION

Evidence and existing guidelines support 29 protocol elements for the Agency for Healthcare Research and Quality Safety Program for Improving Surgical Care and Recovery in gynecologic surgery.

Alvimopan, Regardless of Ileus Risk, Significantly Impacts Ileus, Length of Stay, and Readmission After Intestinal Surgery

BACKGROUND

Previous analyses evaluating alvimopan included patients at varying risk for ileus after intestinal resection, which may have precluded its widespread adoption. We assess the early and delayed effects of alvimopan in patients stratified by risk for ileus after intestinal and colon resection.

METHODS

From the Premier Perspective database, patients with elective small and large bowel resections from 2012 to 2014 were identified. Multivariable analysis identified 14 perioperative risk factors for postoperative ileus. Within low- (0-4 factors), intermediate- (5 factors), and high-risk (6-12 factors) ileus categories, alvimopan and no-alvimopan patients were propensity-score matched for demographics, morbidities, diagnosis, surgery and approach, postoperative complications, surgeon specialty, and hospital features. In-hospital postoperative ileus, length of stay, discharge destination, and ileus-related readmission were compared.

RESULTS

Of 52,948 patients, 15,719 (29.7%) received alvimopan. Risk for ileus in low- (18,784), intermediate- (14,370), and high-risk (19,794) categories was 8.9, 13, and 22% (p ≤ .0001) respectively. After matching, alvimopan was associated with significantly reduced in-hospital postoperative ileus in all (low, 6%; intermediate, 9.4%; and high risk, 16.2%) categories. Hospital stay and 30-, 60-, and 90-day postdischarge ileus were also significantly lower with alvimopan. For low-risk patients, alvimopan increased discharge to home, while 90-day emergency readmission was reduced.

CONCLUSIONS

Alvimopan, regardless of ileus risk, improves ileus, hospital stay, and ileus-related readmission after intestinal resection and these effects are sustained over the long term. Since fewer than a third of patients currently receive alvimopan, its routine adoption with small and large intestinal resection will significantly impact patients and health systems.

Evaluation of Healthcare Use and Clinical Outcomes of Alvimopan in Patients Undergoing Bowel Resection: A Propensity Score-Matched Analysis

BACKGROUND

Postoperative ileus is a significant complication after bowel resection surgeries. Alvimopan is the only US Food and Drug Administration-approved therapy for accelerating the return of bowel function after large- and small-bowel resection.

OBJECTIVE

The purpose of this study was to estimate the healthcare use and in-hospital morbidities associated with on-label use of alvimopan in patients undergoing bowel resection surgeries.

DESIGN

A retrospective observational propensity-matched cohort study was conducted using a large hospital administrative database.

SETTING

The study included inpatient postsurgical patients.

PATIENTS

Patients aged ≥18 years undergoing a primary large or small segmental bowel resection with discharge dates between January 2010 and December 2014 were included.

INTERVENTIONS

Patients receiving 2 to 15 doses of alvimopan were defined as the treatment cohort, and those without any alvimopan use were included as control subjects.

MAIN OUTCOME MEASURES

The primary outcome was postoperative length of stay. Secondary outcomes included postoperative in-hospital morbidities, inpatient mortality, intensive care unit length of stay, discharge disposition, and 30-day readmission.

RESULTS

Each propensity-score matched cohort included 18,559 patients. The mean (±SD) postoperative length of stay was 4.62 ± 2.45 days in alvimopan-treated patients compared with 5.24 ± 3.35 days in control subjects (p < 0.001). Alvimopan-treated patients had lower rates of postoperative GI complication (12.15% vs 16.50%; p < 0.001). The rates of urinary tract infections; other postoperative infections; and cardiovascular, pulmonary, thromboembolic, and cerebrovascular events were also lower compared with the control subjects.

LIMITATIONS

The study was limited by its inability to generalize to the US population, because the database included a convenience sample of hospital discharges. The identification of patients undergoing bowel resection and their clinical conditions relied on the accuracy and completeness of International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis and procedure coding. There may be a confounding effect by the use of enhanced recovery pathways associated with the use of alvimopan.

CONCLUSIONS

The use of alvimopan was associated with a reduction of 0.62 days in postsurgery length of stay and lower rates of postoperative GI complications, infections, and other in-hospital morbidities. See Video Abstract at http://links.lww.com/DCR/A703.

A Retrospective Study of Patients Undergoing Radical Cystectomy and Receiving Peri-Operative Naloxegol or Alvimopan: Comparison of Length of Stay

Alvimopan is a μ-opioid receptor antagonist used in the post-operative period to decrease rates of post-operative ileus (POI) following radical cystectomy (RC) and thereby shorten length of stay (LOS). Naloxegol is a much less expensive drug of the same class that has yet to be studied for prevention of POI in the peri-operative period. The purpose of the current study is to evaluate the differences in LOS and development of POI in patients post-RC who take alvimopan versus those who take naloxegol, with the hope that drug efficacy can be evaluated against the significant difference in cost burden between the two drugs. The study population included all adult patients between 18-89 years of age with bladder cancer undergoing radical cystectomy with urostomy at University of Colorado Hospital. Those patients who received usual post-operative care as well as either alvimopan or naloxegol between September 2011 and December 2017 were selected for analysis. Patients who did not take either medication or were switched from one drug to the other were excluded from the study. A zero-truncated binomial regression analysis was used to analyze differences in length of stay in patients who received alvimopan versus those who received naloxegol. Additionally, the incidence of post-operative ileus was compared between treatment groups. 130 patients who underwent RC and received either alvimopan or naloxegol were included in the study: 75 (58%) received alvimopan and 55 (42%) received naloxegol. Baseline characteristics were similar between treatment groups. There was no significant difference in the length of stay between patients who received alvimopan and patients who received naloxegol after adjusting for age, sex, BMI, length of surgical time, or stage of disease (p = 0.41). There was no significant between the two drugs for development of POI (p = 0.85). Development of POI was significantly associated with a longer LOS (p = 0.007). The analysis showed that naloxegol was comparable to alvimopan when it came to length of hospital stay following RC. Therefore, naloxegol may be offered as a less expensive, effective alternative to alvimopan.

The Efficacy of Peripheral Opioid Antagonists in Opioid-Induced Constipation and Postoperative Ileus: A Systematic Review of the Literature

Opioid-induced constipation has a negative impact on quality of life for patients with chronic pain and can affect more than a third of patients. A related but separate entity is postoperative ileus, which is an abnormal pattern of gastrointestinal motility after surgery. Nonselective μ-opioid receptor antagonists reverse constipation and opioid-induced ileus but cross the blood-brain barrier and may reverse analgesia. Peripherally acting μ-opioid receptor antagonists target the μ-opioid receptor without reversing analgesia. Three such agents are US Food and Drug Administration approved. We reviewed the literature for randomized controlled trials that studied the efficacy of alvimopan, methylnaltrexone, and naloxegol in treating either opioid-induced constipation or postoperative ileus. Peripherally acting μ-opioid receptor antagonists may be effective in treating both opioid-induced bowel dysfunction and postoperative ileus, but definitive conclusions are not possible because of study inconsistency and the relatively low quality of evidence. Comparisons of agents are difficult because of heterogeneous end points and no head-to-head studies.

The effect of simethicone on postoperative ileus in patients undergoing colorectal surgery (SPOT), a randomized controlled trial

BACKGROUND

Postoperative ileus is a poorly understood multifactorial outcome following colorectal surgery that presents significant clinical challenges and contributes to increased morbidity, length of stay, and healthcare cost. To date, there are few pharmacological interventions that shorten the duration of postoperative ileus.

OBJECTIVE

This study is the first to evaluate the efficacy of simethicone in treating postoperative ileus symptoms in patients undergoing colorectal surgery.

DESIGN

A multicenter, double-blinded, placebo controlled randomized controlled trial.

SETTINGS

This trial was conducted at two academic tertiary care centres in Ontario, Canada.

PARTICIPANTS

118 patients undergoing colorectal surgery.

INTERVENTIONS

Patients were randomized to receive either a five-day course of oral simethicone (n = 58) or a placebo (n = 60).

MAIN OUTCOME MEASURES

The primary outcome was time to first passage of flatus. Secondary outcomes included time to first bowel movement, postoperative length of stay, and postoperative pain. Statistical analyses were performed on an intention-to-treat basis. Statistical significance set at p = 0.05.

RESULTS

The median time to first passage of flatus in simethicone arm was 25.2 h and 26.7 h in controls (P = 0.98). There were no significant differences in the median time to first bowel movement (simethicone = 41.1 h vs. control = 42.9 h, P = 0.91) or median length of hospital stay (simethicone = 4.5 days vs. control = 4.0 days, P = 0.63).

CONCLUSIONS

This study failed to show a difference in return of gastrointestinal motility in patients receiving simethicone following colorectal surgery. Postoperative ileus remains a significant clinical and economic burden to the healthcare system and further research is needed to identify a reliable and effective method of treatment.

Postoperative ileus following major colorectal surgery

BACKGROUND

Postoperative ileus (POI) is characterized by delayed gastrointestinal recovery following surgery. Current knowledge of pathophysiology, clinical interventions and methodological challenges was reviewed to inform modern practice and future research.

METHODS

A systematic search of MEDLINE and Embase databases was performed using search terms related to ileus and colorectal surgery. All RCTs involving an intervention to prevent or reduce POI published between 1990 and 2016 were identified. Grey literature, non-full-text manuscripts, and reanalyses of previous RCTs were excluded. Eligible articles were assessed using the Cochrane tool for assessing risk of bias.

RESULTS

Of 5614 studies screened, 86 eligible articles describing 88 RCTs were identified. Current knowledge of pathophysiology acknowledges neurogenic, inflammatory and pharmacological mechanisms, but much of the evidence arises from animal studies. The most common interventions tested were chewing gum (11 trials) and early enteral feeding (11), which are safe but of unclear benefit for actively reducing POI. Others, including thoracic epidural analgesia (8), systemic lidocaine (8) and peripheral μ antagonists (5), show benefit but require further investigation for safety and cost-effectiveness.

CONCLUSION

POI is a common condition with no established definition, aetiology or treatment. According to current literature, minimally invasive surgery, protocol-driven recovery (including early feeding and opioid avoidance strategies) and measures to avoid major inflammatory events (such as anastomotic leak) offer the best chances of reducing POI.

Gastrointestinal motility dysfunction in critically ill patients: Pathogenesis, clinical assessment, and treatment

Gastrointestinal motility dysfunction is a common clinical complication in ICU patients, which can lead to difficulty in enteral nutrition, vomiting, diarrhea, increased intra-abdominal pressure, ventilator associated pneumonia, intestinal flora displacement, and other adverse reactions. The clinical features of gastrointestinal dysfunction mainly include gastric emptying disturbance, intestinal dysfunction, and gastrointestinal motility disorders. The causes of gastrointestinal motility dysfunction in ICU patients are complex and the clinical evaluation of gastrointestinal dysfunction is difficult. These factors have led to the fact that gastrointestinal motility monitoring techniques have not been widely used in clinical practice. Timely detection and correction of gastrointestinal motility dysfunction in ICU patients can improve outcomes. This article reviews the etiology, clinical evaluation, and treatment of gastrointestinal motility dysfunction in ICU patients.

Alvimopan Provides Additional Improvement in Outcomes and Cost Savings in Enhanced Recovery Colorectal Surgery

OBJECTIVE

To examine the impact of alvimopan on outcomes and costs in a rigorous enhanced recovery colorectal surgery protocol.

BACKGROUND

Postoperative ileus remains a major source of morbidity and costs in colorectal surgery. Alvimopan has been shown to reduce incidence of postoperative ileus in enhanced recovery colorectal surgery; however, data are equivocal regarding its benefit in reducing length of stay and costs.

METHODS

Patients undergoing major elective enhanced recovery colorectal surgery were identified from a prospectively-collected database (2010-2013). Multivariable analyses were employed to compare outcomes and hospital costs among patients who had alvimopan versus no alvimopan by adjusting for demographic, clinical, and treatment characteristics.

RESULTS

A total of 660 patients were included; 197 patients received alvimopan and 463 patients had no alvimopan. In unadjusted analysis, the alvimopan group had a faster return of bowel function, shorter length of stay, and lower rates of ileus, Foley re-insertion, and urinary tract infection (all P < 0.01). After adjustment, alvimopan was associated with a faster return of bowel function by 0.6 day (P = 0.0006), and lower incidence of postoperative ileus (odds ratio 0.23, P = 0.0002). With adjustment, alvimopan was associated with a shorter length of stay by 1.6 days (P = 0.002), and a hospital cost savings of $1492 per patient (P = 0.01).

CONCLUSIONS

Alvimopan administration as an element of enhanced recovery colorectal surgery is associated with faster return of bowel function, lower incidence of postoperative ileus, shorter hospitalization, and a significant cost savings. These results suggest that alvimopan is cost-effective in the setting of enhanced recovery colorectal surgery protocols, and should therefore be considered in these programs.

Bowel Sounds Are Not Associated With Flatus, Bowel Movement, or Tolerance of Oral Intake in Patients After Major Abdominal Surgery

BACKGROUND

Auscultation for bowel sounds has been advocated by some clinicians as a method to determine the resolution of postoperative ileus.

OBJECTIVE

Our primary aim was to prospectively evaluate the relationships between bowel sounds and the ability to tolerate oral intake in patients after major abdominal surgery. Secondarily we aimed to evaluate relationships among bowel sounds, flatus and bowel movement, and oral intake.

DESIGN

This was a prospective, blinded observational study.

SETTINGS

The study was conducted at Western Pennsylvania Hospital.

PATIENTS

A total of 124 adult patients undergoing major abdominal surgery were included.

MAIN OUTCOME MEASURES

Data were collected by medical students blinded to the purpose of the study for 10 days postoperatively or until discharge, including the presence of bowel sounds (auscultation for 1 minute), flatus, bowel movement, and tolerance of oral intake (defined as ingestion of ≥1000 mL/24 h and each subsequent day without vomiting). Associations between paired variables were determined using ϕ coefficient testing.

RESULTS

The study population consisted of 51 men and 73 women, with a mean age of 64 years (range, 20-92 y). The majority of patients (78/124 (63%)) underwent colorectal resection. The median length of hospital was 6 days. Bowel sounds were not associated with flatus, bowel movement, or tolerance of oral intake throughout the study period. The positive predictive value of bowel sounds in predicting flatus and bowel movement was low in the early postoperative period and remained <25% in predicting tolerance of oral intake throughout the study period. The analysis was repeated, including only those patients undergoing colorectal procedures, and was essentially unchanged. Flatus correlated with bowel movement in the first 6 days postoperation, but neither flatus nor bowel movement was associated with tolerance of oral intake.

LIMITATIONS

The rate of tolerance of oral intake was relatively modest throughout the study period.

CONCLUSIONS

Bowel sounds are not associated with flatus, bowel movement, or tolerance of oral intake after major abdominal surgery.

Cost and efficacy examination of alvimopan for the prevention of postoperative ileus

Opioid analgesics exacerbate ileus through peripheral μ-opioid receptor action. Alvimopan, a μ-opioid receptor antagonist, has been proposed to alleviate postoperative ileus, leading to decreased time to return of gastrointestinal function and hospital discharge. As opioid-induced motility issues are only one factor affecting postoperative ileus, continued examination of the cost of the use and efficacy of the drug is needed. Data for this study were collected retrospectively from the charts of 55 patients who received an anastomosis and were given alvimopan at Morristown Medical Center between 2010 and 2013 as well as from 58 appropriately matched controls. The billing record and chart for each patient was examined, and information on total hospital charges, age, sex, body mas index, primary diagnosis, procedure type, length of stay (days), time to return of bowel function (hours), and outcomes were recorded for analysis. No difference between patients given alvimopan and controls was observed for the length of hospital stay (4.6 vs 4.8 days) or for time to return of bowel function (68.5 vs 67.3 hours). Total hospital charges were higher for treated patients (p=0.0080), averaging $48 705.15 and $41 068.80, respectively. Alvimopan was not associated with improved clinical outcome but was associated with an increase in hospital charges within this population.

Alvimopan for recovery of bowel function after radical cystectomy

BACKGROUND

Alvimopan is used in abdominal surgery to reduce postoperative ileus in patients undergoing small bowel resections with primary anastomosis. The role and efficacy of alvimopan in patients undergoing radical cystectomy with urinary diversion is not well understood.

OBJECTIVES

To assess the effects of alvimopan in the context of enhanced recovery pathways compared to enhanced recovery pathways alone for perioperative bowel dysfunction in patients undergoing radical cystectomy.

SEARCH METHODS

The terms alvimopan and cystectomy were used to search the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase. We also reviewed abstracts from the past four years (2013 to 2016) of the American Urologic Association, Society of Urologic Oncology, and American Society of Clinical Oncology Genitourinary Cancers.

SELECTION CRITERIA

We searched for randomized controlled trials that compared alvimopan to placebo.

DATA COLLECTION AND ANALYSIS

This study was based on a published protocol. We performed a comprehensive search of multiple databases including CENTRAL in the Cochrane Library, MEDLINE, Embase, LILACS, Web of Science, Scopus and Biosis, which we last updated on 6 February 2017. We also searched abstract proceedings for major relevant meetings (2013 to 2016), databases of the grey literature, trial registries, citations of relevant reviews and contacted clinical experts and the drug manufacturer.Two independent reviewers screened the literature in two stages (title and abstract, full-text) using Covidence software. Two independent reviewers assessed the risk of bias on a 'per outcome' basis using the Cochrane 'Risk of bias; tool and rated the quality of evidence according to GRADE. Results of the single eligible trial were reported in a 'Summary of findings' table based on an intention-to-treat analysis.

MAIN RESULTS

Based on a single trial and moderate-quality evidence, alvimopan reduced the time to reach a composite endpoint of tolerance of solid food and documented bowel movements (hazard ratio (HR) 1.77, 95% confidence interval (CI) 1.41 to 2.23). This represents 165 more patients (109 more to 207 more) per 1000 meeting this endpoint within 10 days of surgery. Based on moderate-quality evidence, alvimopan reduced the time to hospital discharge (HR 1.67, 95% CI 1.38 to 2.01). This represents 138 more patients (82 more to 198 more) per 1000 being discharged within 10 days of surgery. Also based on moderate-quality evidence, alvimopan was associated with a reduced risk of major adverse events (risk ratio (RR) 0.28, 95% CI 0.18 to 0.44) representing 355 fewer patients (404 fewer to 276 fewer) with major adverse events per 1000. We downgraded this outcome for indirectness as it included adverse events that we did not consider major.In terms of secondary outcomes, alvimopan did not appear to alter the rate of readmission (RR 0.89, 95% CI 0.59 to 1.33), change the rate of any cardiovascular event (RR 0.54, 95% CI 0.27 to 1.05) or alter the mean narcotic pain medication use (mean difference 0, 95% CI 14.08 fewer to 14.08 more morphine equivalents). The quality of evidence was moderate for all three outcomes. Based on high-quality evidence, alvimopan reduced the rate of nasogastric tube replacement (RR 0.31, 95% CI 0.16 to 0.59). We did not find evidence for the drug's impact on rates of parenteral nutrition. All outcomes were short term and limited to a 30-day time horizon.Based on the existence of only one trial, we were unable to perform any subgroup or sensitivity analyses.

AUTHORS' CONCLUSIONS

In patients undergoing radical cystectomy and urinary diversion, the use of alvimopan administered as part of an enhanced recovery pathway for a limited duration (up to 15 doses for up to seven days) probably reduces the time to tolerance of solid food, time to hospital discharge and rates of major adverse events. Readmission rates, rates of cardiovascular events and narcotic pain requirements are probably similar. The need for reinsertion of nasogastric tubes is reduced. We found no evidence for the impact on rates of parenteral nutrition within 30 postoperative days.

Alvimopan in the setting of colorectal resection with an ostomy: To use or not to use?

BACKGROUND

Postoperative ileus (POI) is a major cause of morbidity, increased length of stay (LOS) and hospital cost after colorectal surgery. Alvimopan is a µ-opioid antagonist used to accelerate upper and lower gastrointestinal function after bowel resection. We hypothesized that alvimopan would reduce LOS in patients undergoing colorectal resection with stoma, a situation that has not been evaluated.

METHODS

A retrospective review (2010-2015) identified 58 patients who underwent colorectal resection for benign or malignant disease with stoma creation and received alvimopan. They were case-matched to 58 non-alvimopan patients based on age, BMI, baseline comorbidities, stoma type created and surgical approach. We compared overall LOS, incidence of POI and other postoperative complications.

RESULTS

There were equal numbers of laparoscopic (N = 18) and open resections (N = 40) in the alvimopan group and non-alvimopan group. There were also equal numbers of patients with an ileostomy (N = 37) or colostomy (N = 21) in each group. Overall, 41 patients underwent resection for malignant disease in the alvimopan group compared to 37 in the non-alvimopan group. There was a significant reduction in median LOS overall (alvimopan 5 (4-7) versus control 6 (4.75-9.25) days, P = 0.03). While the 6-day median LOS was similar for patients undergoing ileostomy creation (P = 0.25), alvimopan patients had a 3-day decreased median LOS that approached statistical significance (P = 0.06). The overall 30-day complication rate was higher in the control group (41.4 vs. 51.7%, P = 0.26), but the readmission rate within 30 days was higher in the alvimopan group (19 vs. 13.8%, P = 0.45). Neither of these differences reached statistically significance.

CONCLUSION

The use of alvimopan in patients undergoing colorectal resection with stoma is associated with a significantly shorter LOS, but the increased readmission rate warrants further study. Based on these data, alvimopan should be evaluated in a controlled setting for patients undergoing colorectal resection with colostomy creation.

Randomized open-label phase II study comparing oxycodone–naloxone with oxycodone in early return of gastrointestinal function after laparoscopic colorectal surgery

Background

Combined oral modified-release oxycodone–naloxone may reduce opioid-induced postoperative gut dysfunction. This study examined the feasibility of a randomized trial of oxycodone–naloxone within the context of enhanced recovery for laparoscopic colorectal resection.

Methods

In a single-centre open-label phase II feasibility study, patients received analgesia based on either oxycodone–naloxone or oxycodone. Primary endpoints were recruitment, retention and protocol compliance. Secondary endpoints included a composite endpoint of gut function (tolerance of solid food, low nausea/vomiting score, passage of flatus or faeces).

Results

Eighty-two patients were screened and 62 randomized (76 per cent); the attrition rate was 19 per cent (12 of 62), leaving 50 patients who received the allocated intervention with 100 per cent follow-up and retention (modified intention-to-treat cohort). Protocol compliance was more than 90 per cent. Return of gut function by day 3 was similar in the two groups: 13 (48 per cent) of 27 in the oxycodone–naloxone group and 15 (65 per cent) of 23 in the control group (95 per cent c.i. for difference −10·0 to 40·7 per cent; P = 0·264). However, patients in the oxycodone–naloxone group had a shorter time to first bowel movement (mean(s.d.) 87(38) h versus 111(37) h in the control group; 95 per cent c.i. for difference 2·3 to 45·4 h, P = 0·031) and reduced total (oral plus parenteral) opioid consumption (mean(s.d.) 78(36) versus 94(56) mg respectively; 95 per cent c.i. for difference −10·2 to 42·8 mg, P = 0·222).

Conclusion

High participation, retention and protocol compliance confirmed feasibility. Potential benefits of oxycodone–naloxone in reducing time to bowel movement and total opioid consumption could be tested in a randomized trial. Registration number: NCT02109640 (https://www.clinicaltrials.gov/).

The use of alvimopan for postoperative ileus in small and large bowel resections

Transient ileus is a normal physiologic process after surgery. When prolonged, it is an important contributor to postoperative complications, increased length of stay and increased healthcare costs. Efforts have been made to prevent and manage postoperative ileus; alvimopan is an oral, peripheral μ-opioid receptor antagonist, and the only currently US FDA-approved medication to accelerate the return of gastrointestinal function postoperatively.

Pharmacological management to prevent ileus in major abdominal surgery: a systematic review and meta-analysis

BACKGROUND

Prolonged ileus is a common complication following gastrointestinal surgery, with an incidence of up to 40 %. Investigations examining pharmacological treatment of ileus have proved largely disappointing; however, recently, several compounds have been shown to have benefited when used as prophylaxis to prevent ileus.

OBJECTIVE

This review aimed to evaluate the safety and efficacy of compounds which have been recently developed or repurposed to reduce bowel recovery time, thereby preventing ileus.

DATA SOURCES

Data were taken from a systematic review of the MEDLINE, EMBASE and Cochrane Library Databases, in addition to manual searching of reference lists up to April 2015. No limits were applied.

STUDY SELECTION

Only randomized trials were eligible for inclusion.

INTERVENTIONS

Opioid receptor antagonists, ghrelin receptor agonists and serotonin receptor agonists used for the prevention of postoperative ileus in gastrointestinal surgery.

MAIN OUTCOME MEASURES

Outcomes of time to first defecation, first flatus and composite bowel recovery endpoints (GI2 and GI3) were used to determine efficacy. Pooled treatment effects were presented as the standard mean difference or as hazard ratios alongside the corresponding 95 % confidence intervals. Risk of bias was assessed using the Cochrane risk of bias framework.

RESULTS

A total of 17 studies were included in the final analysis. The μ-opioid receptor antagonist alvimopan and serotonin receptor agonists appeared to significantly shorten the duration of ileus. The use of Ghrelin receptor agonists did not appear to have any effect in five trials. No publication bias was detected.

LIMITATIONS

Most of the trials were poorly reported and of mixed quality. Future studies must focus on the development of a set of core outcomes.

CONCLUSIONS

There is evidence to make a strong recommendation for the use of alvimopan in major gastrointestinal surgery to reduce postoperative ileus. Further randomized trials are required to establish whether serotonin receptor agonists are of use. Identifying a low-cost compound to promote bowel recovery following surgery could reduce complications and shorten duration of hospital admissions.

Is there value in alvimopan in minimally invasive colorectal surgery?

BACKGROUND

Alvimopan's goal is to minimize postoperative ileus and optimize outcomes; however, evidence in laparoscopic surgery is lacking. Our goal was to evaluate the benefit of alvimopan in laparoscopic colorectal surgery with an enhanced recovery pathway (ERP).

METHODS

Laparoscopic colorectal cases were stratified into alvimopan and control cohorts, then case-matched for comparability. All followed an identical ERP. The main outcomes were length of stay, complications, readmissions, and costs in the alvimopan and control groups.

RESULTS

About 321 patients were analyzed in each cohort. Operative times were comparable (P = .08). Postoperatively, complication rates were similar (P = .29), with no difference in ileus (P = 1.00). The length of stay (3.69 vs 3.49 days; P = .16), readmission (2.8% vs 3.7%; P = .66) and reoperation rates (2.2% vs 1.6%; P = .77) were comparable for alvimopan and controls, respectively. Total costs were similar ($14,932.47 alvimopan vs $14,846.56 controls; P = .90), but the additional costs in the alvimopan group could translate to savings of $27,577 in the cohort.

CONCLUSIONS

Alvimopan added no benefit in patient outcomes in laparoscopic colorectal surgery with an ERP. These results could drive a change in current practice. Controlled studies are warranted to define the cost and/or benefit in clinical practice.

[Current issues on the treatment of chronic constipation]

Chronic constipation is a very common clinical problem with its prevalence of up to 14% in the general population. It is not a life-threatening disease, but since patient's satisfaction to the treatment is known to be as low as 50%, chronic constipation still remains a clinically challenging problem. Fortunately, many new treatments have been introduced or are to be introduced in the near future. This article will review the basic concepts and the results of recent studies on the new treatments for chronic constipation.

Alvimopan combined with enhanced recovery strategy for managing postoperative ileus after open abdominal surgery: a systematic review and meta-analysis

BACKGROUND

To assess the efficacy and safety of alvimopan in conjunction with enhanced recovery strategy, compared with this strategy alone, in management of postoperative ileus in patients undergoing open abdominal surgery.

METHODS

Electronic databases were comprehensively searched for relevant randomized controlled trials. We were interested in doses of 6 and 12 mg. The efficacy end points included the time to recovery of full gastrointestinal (GI) function (a composite end point measured by the time to first toleration of solid food [SF] and the time to first passage of stool, GI-2), the recovery of upper (SF) or the lower (the time to first bowel movement, BM) GI function, and the length of hospital stay (the time to discharge order written). Safety end points included GI-related, non-GI-related, and serious adverse events. These parameters were all analyzed by RevMan 5.3 software.

RESULTS

Nine randomized controlled trials involving 4075 patients were enrolled in this study. The pooled results showed that alvimopan significantly decreased the time to GI-2 recovery (6 mg, hazard ratio [HR] = 1.45, P < 0.00001; 12 mg, HR = 1.59, P < 0.00001), BM (6 mg, HR = 1.54, P < 0.00001; 12 mg, HR = 1.74, P = 0.0002), and the time to discharge order written (6 mg, HR = 1.37, P < 0.00001; 12 mg, HR = 1.34, P < 0.00001) compared with the placebo group. However, SF was significantly reduced in 6 mg group (HR = 1.23, P = 0.008) rather than 12 mg group (HR = 1.14, 95% confidence interval 1.00, 1.30, P = 0.04). The incidence of some GI-related and serious adverse events were significantly lower in the alvimopan group than the placebo group, and the dose of 12 mg was superior to 6 mg in this regard.

CONCLUSIONS

Alvimopan can accelerate recovery of GI function (especially for the lower GI tract), shorten the length of hospital stay, and reduce postoperative ileus-related morbidity without compromising opioid analgesia in an enhanced recovery setting.

Alvimopan Use, Outcomes, and Costs: A Report from the Surgical Care and Outcomes Assessment Program Comparative Effectiveness Research Translation Network Collaborative

BACKGROUND

Randomized trials have found that alvimopan hastens return of bowel function and reduces length of stay (LOS) by 1 day among patients undergoing colorectal surgery. However, its effectiveness in routine clinical practice and its impact on hospital costs remain uncertain.

STUDY DESIGN

We performed a retrospective cohort study of patients undergoing elective colorectal surgery in Washington state (2009 to 2013) using data from a clinical registry (Surgical Care and Outcomes Assessment Program) linked to a statewide hospital discharge database (Comprehensive Hospital Abstract Reporting System). We used generalized estimating equations to evaluate the relationship between alvimopan and outcomes, and adjusted for patient, operative, and management characteristics. Hospital charges were converted to costs using hospital-specific charge to cost ratios, and were adjusted for inflation to 2013 US dollars.

RESULTS

Among 14,781 patients undergoing elective colorectal surgery at 51 hospitals, 1,615 (11%) received alvimopan. Patients who received alvimopan had a LOS that was 1.8 days shorter (p < 0.01) and costs that were $2,017 lower (p < 0.01) compared with those who did not receive alvimopan. After adjustment, LOS was 0.9 days shorter (p < 0.01), and hospital costs were $636 lower (p = 0.02) among those receiving alvimopan compared with those who did not.

CONCLUSIONS

When used in routine clinical practice, alvimopan was associated with a shorter LOS and limited but significant hospital cost savings. Both efficacy and effectiveness data support the use of alvimopan in routine clinical practice, and its use could be measured as a marker of higher quality care.