Alvimopan, a novel, peripherally acting mu opioid antagonist: results of a multicenter, randomized, double-blind, placebo-controlled, phase III trial of major abdominal surgery and postoperative ileus

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.

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.

Gastrointestinal Complications Following Radical Cystectomy Using Enhanced Recovery Protocol

BACKGROUND

The development of enhanced recovery after surgery (ERAS) protocols for patients undergoing radical cystectomy (RC) represents a significant advance in perioperative care.

OBJECTIVE

To evaluate gastrointestinal (GI) complications following RC and urinary diversion (UD) using our institutional ERAS protocol.

DESIGN, SETTING, AND PARTICIPANTS

We identified 377 consecutive cases of open RC and UD for which our ERAS protocol was used from May 2012 to December 2015. Exclusion criteria were consent refusal; non-bladder primary disease; palliative, salvage, or additional surgery; and prolonged postoperative intubation. A matched cohort of 144 patients for whom a traditional postoperative protocol (pre-ERAS) was used between 2003 and 2012 was selected for comparison.

RESULTS AND LIMITATIONS

A total of 292 ERAS patients with median age of 70 yr were included in the study, 65% of whom received an orthotopic neobladder. The median time to first flatus and bowel movement was 2 d. The median length of stay was 4 d. GI complications occurred in 45 patients (15.4%) during the first 30 d following RC, 93% of which were of minor grade. The most common GI complication was postoperative ileus (POI) in 34 cases (11.6%). Some 22 patients (7.5%) required a nasogastric tube, and parenteral nutrition was required in three patients. The rate of 30-d GI complications was significantly lower in the ERAS cohort than in the control group (13% vs 27%; p=0.003), as was the rate of POI (7% vs 23%; p<0.001). This effect was independent of other variables (hazard ratio 0.38, 95% confidence interval 0.18-0.82; p=0.01).

CONCLUSIONS

Our institutional ERAS protocol for RC is associated with significantly improved perioperative GI recovery and lower rates of GI complications. This protocol can be tested in multi-institutional studies to reduce GI morbidity associated with RC.

PATIENT SUMMARY

In this study, we showed that an enhanced recovery protocol for patients undergoing radical cystectomy for bladder cancer was associated with a significantly shorter length of hospital stay and lower rates of gastrointestinal complications, especially postoperative ileus.

Nicotine chewing gum for the prevention of postoperative ileus after colorectal surgery: a multicenter, double-blind, randomised, controlled pilot study

PURPOSE

When postoperative ileus is not resolved after 5 days or recurs after resolution, prolonged POI (PPOI) is diagnosed. PPOI increases discomfort, morbidity and hospitalisation length, and is mainly caused by an inflammatory response following intestinal manipulation. This response can be weakened by targeting the cholinergic anti-inflammatory pathway, with nicotine as essential regulator. Chewing gum, already known to stimulate gastrointestinal motility itself, combined with nicotine is hypothesised to improve gastrointestinal recovery and prevent PPOI. This pilot study is the first to assess efficacy and safety of nicotine gum in colorectal surgery.

METHODS

Patients undergoing elective oncological colorectal surgery were enrolled in this double-blind, parallel-group, controlled trial and randomly assigned to a treatment protocol with normal or nicotine gum (2 mg). Patient reported outcomes (PROMS), clinical characteristics and blood samples were collected. Primary endpoint was defined as time to first passage of faeces and toleration of solid food for at least 24 h.

RESULTS

In total, 40 patients were enrolled (20 vs. 20). In both groups, six patients developed PPOI. Time to primary endpoint (4.50 [3.00-7.25] vs. 3.50 days [3.00-4.25], p = 0.398) and length of stay (5.50 [4.00-8.50] vs. 4.50 days [4.00-6.00], p = 0.738) did not differ significantly between normal and nicotine gum. There were no differences in PROMS, inflammatory parameters and postoperative complications.

CONCLUSIONS

We proved nicotine gum to be safe but ineffective in improving gastrointestinal recovery and prevention of PPOI after colorectal surgery. Other dosages and administration routes of nicotine should be tested in future research.

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.

Gastrointestinal Complications in Patients Who Undergo Radical Cystectomy with Enhanced Recovery Protocol

Gastrointestinal (GI) complications are among the most common complications following radical cystectomy and urinary diversion. The most common is postoperative ileus, although its precise pathophysiology is not completely understood. Enhanced recovery after surgery (ERAS) protocols include evidence-based steps to optimize postoperative recovery and shorten hospital stay, mainly through expedited GI function recovery. They include avoiding bowel preparation and postoperative nasogastric tube, early feeding, non-narcotic pain management, and the use of cholinergic and mu-receptor opioid antagonists. We reviewed the literature in regard to GI complications using enhanced recovery protocols and share our institutional experience with over 300 patients.

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.

Gastrointestinal dysmotility disorders in critically ill dogs and cats

OBJECTIVE

To review the human and veterinary literature regarding gastrointestinal (GI) dysmotility disorders in respect to pathogenesis, patient risk factors, and treatment options in critically ill dogs and cats.

ETIOLOGY

GI dysmotility is a common sequela of critical illness in people and small animals. The most common GI motility disorders in critically ill people and small animals include esophageal dysmotility, delayed gastric emptying, functional intestinal obstruction (ie, ileus), and colonic motility abnormalities. Medical conditions associated with the highest risk of GI dysmotility include mechanical ventilation, sepsis, shock, trauma, systemic inflammatory response syndrome, and multiple organ failure. The incidence and pathophysiology of GI dysmotility in critically ill small animals is incompletely understood.

DIAGNOSIS

A presumptive diagnosis of GI dysmotility is often made in high-risk patient populations following detection of persistent regurgitation, vomiting, lack of tolerance of enteral nutrition, abdominal pain, and constipation. Definitive diagnosis is established via radioscintigraphy; however, this diagnostic tool is not readily available and is difficult to perform on small animals. Other diagnostic modalities that have been evaluated include abdominal ultrasonography, radiographic contrast, and tracer studies.

THERAPY

Therapy is centered at optimizing GI perfusion, enhancement of GI motility, and early enteral nutrition. Pharmacological interventions are instituted to promote gastric emptying and effective intestinal motility and prevention of complications. Promotility agents, including ranitidine/nizatidine, metoclopramide, erythromycin, and cisapride are the mainstays of therapy in small animals.

PROGNOSIS

The development of complications related to GI dysmotility (eg, gastroesophageal reflux and aspiration) have been associated with increased mortality risk. Institution of prophylaxic therapy is recommended in high-risk patients, however, no consensus exists regarding optimal timing of initiating prophylaxic measures, preference of treatment, or duration of therapy. The prognosis for affected small animal patients remains unknown.

Prevention of Paralytic Ileus Utilizing Alvimopan Following Spine Surgery

Postoperative ileus affects a substantial proportion of patients undergoing elective spine surgery, especially in cases of spinal deformity correction and where an anterior lumbar approach is utilized. Though the first line of treatment for postoperative ileus is conservative management, recent advances in pharmacology have yielded promising options for both treatment and prevention. We report a case of a patient who underwent a two-stage posterior spinal fusion. The patient suffered with a severe, prolonged ileus after her initial surgery. To prevent ileus following her second spinal surgery, alvimopan (a µ-opioid receptor antagonist) was administered and she had a rapid return of bowel function with no signs of ileus. Alvimopan, has been shown to reduce the rate of ileus in colorectal surgery patients, and may be useful for preventing ileus in high-risk orthopedic and spine surgery patients, although prospective studies will be needed to test this hypothesis.

Radical Cystectomy Perioperative Care Redesign

OBJECTIVE

To present an evidence-based review of the perioperative management of the radical cystectomy (RC) patient in the context of a care redesign initiative.

METHODS

A comprehensive review of the key factors associated with perioperative management of the RC patient was completed. PubMed, Medline, and the Cochrane databases were queried via a computerized search. Specific topics were reviewed within the scope of the three major phases of perioperative management: preoperative, intraoperative, and postoperative. Preference was given to evidence from prospective randomized trials, meta-analyses, and systematic reviews.

RESULTS

Preoperative considerations to improve care in the RC patient should include multi-disciplinary medical optimization, patient education, and formal coordination of care. Efforts to mitigate the risk of malnutrition and reduce postoperative gastrointestinal complications may include carbohydrate loading, protein nutrition supplementation, and avoiding bowel preparation. Intraoperatively, a fluid and opioid sparing protocol may reduce fluid shifts and avoid complications from paralytic ileus. Finally, enhanced recovery protocols including novel medications, early feeding, and multi-modal analgesia approaches are associated with earlier postoperative convalescence.

CONCLUSION

RC is a complex and morbid procedure that may benefit from care redesign. Evidence based quality improvement is integral to this process. We hope that this review will help guide further improvement initiatives for RC.

Delayed gastrointestinal recovery after abdominal operation - role of alvimopan

Postoperative Ileus (POI), which occurs after surgical manipulation of the bowel during abdominal operations, is associated with prolonged hospital stay, increasing medical costs, and delayed advancement of enteral diet, which contributes to a significant economic burden on the healthcare system. The use of accelerated care pathways has shown to positively impact gut function, but inevitable postoperative opioid use contributes to POI. Alvimopan is a peripherally acting μ-opioid receptor antagonist designed to mitigate antimotility effects of opioids. In our review, we examined ten trials on alvimopan’s use after abdominal operations. Several of the earlier studies on patients undergoing bowel resection showed correlations between the study group and GI recovery as defined by passage of flatus, first bowel movement, and time to readiness for discharge. Data in patients undergoing total abdominal hysterectomy showed similarly decreased GI recovery time. Additionally, data within the past few years shows alvimopan is associated with more rapid GI recovery time in patients undergoing radical cystectomy. Based on our review, use of alvimopan remains a safe and potentially cost-effective means of reducing POI in patients following open GI surgery, radical cystectomy, and total abdominal hysterectomy, and should be employed following these abdominal operations.

Off-label uses of alvimopan and methylnaltrexone

PURPOSE

Off-label uses of the peripheral μ-opioid receptor antagonists alvimopan and methylnaltrexone are reviewed.

SUMMARY

Alvimopan is approved by the Food and Drug Administration (FDA) for postoperative ileus after surgeries that include partial bowel resection with primary anastomosis, while methylnaltrexone is approved for the treatment of opioid-induced constipation (OIC) in patients with advanced illness who are receiving palliative care. Literature describing the off-label use of alvimopan in the treatment of OIC and of methylnaltrexone in postoperative ileus was reviewed and included retrospective studies and prospective Phase II-IV trials. Randomized controlled trials did not demonstrate consistent benefit of alvimopan in OIC nor of methylnaltrexone in postoperative ileus. A greater proportion of patients receiving alvimopan for OIC experienced severe adverse cardiovascular events, leading to a risk evaluation and mitigation strategy and discontinuation of its study in this condition. Data are limited and unreplicated for the off-label use of alvimopan for postoperative ileus in patients undergoing abdominal hysterectomy. Individual studies suggest benefit with methylnaltrexone for OIC in unlabeled populations, including patients with non-cancer-related pain, opioid dependence, opioid sedation, and opioid use after orthopedic surgery; however, confirmatory evaluations have not been performed.

CONCLUSION

Trials of alvimopan in the FDA-approved use of methylnaltrexone (OIC) indicate potentially serious cardiovascular safety concerns and conflicting findings of efficacy. Similarly, trials of methylnaltrexone in the FDA-approved use of alvimopan (postoperative ileus) consistently showed no benefit. Evaluations of both drugs in their labeled conditions in populations not endorsed in their product labeling have been limited and largely unreplicated.

Surgical advances in bladder cancer: at what cost?

Bladder cancer is the most expensive cancer to treat from diagnosis to death. Frequent disease recurrence, intense follow-up, and expensive, invasive techniques for diagnosis and treatment drive these costs for non-muscle invasive bladder cancer. Fluorescence cystoscopy increases the detection of superficial bladder cancer and reduces costs by improving the quality of resection and reducing recurrences. Radical cystectomy with intestinal diversion is the mainstay of treatment of invasive disease; however it is associated with substantial cost and morbidity. Increased efforts to improve the surgical management of bladder cancer while reducing the cost of treatment are increasingly necessary.

Does alvimopan enhance return of bowel function in laparoscopic gastrointestinal surgery? A meta-analysis

BACKGROUND

Postoperative ileus (POI) remains a major impediment in patient recovery and leads to longer lengths of stay at the hospital, readmission rates, and hospital costs. Alvimopan, a mu-opioid receptor antagonist, lowers POI incidence following open gastrointestinal surgery, however, little is known about its role on POI prevention among patients undergoing laparoscopic gastrointestinal surgery.

METHODS

A comprehensive search of PubMed/MEDLINE, Scopus, CINAHL, and Cochrane databases was performed (December 2014). Meta-analysis was performed using the Mantel-Haenszel (fixed effects) model with odds ratio (OR) to assess prevention of POI and hospital readmission.

RESULTS

Five studies were included in the final analysis. Pooling 4 of 5 studies, there was over a 75% relative risk reduction in POI development when patients were given alvimopan compared to placebo (OR 0.24, 95%CI 0.12-0.51, P=0.02). The number needed to treat with alvimopan to prevent one POI episode was 11 patients. There was a modest reduction in the length of hospitalization between 0.2 and 1.6 days. There did not appear to be a difference in frequency of 30-day readmission rate among the alvimopan group compared to placebo (OR 1.15, 95%CI 0.54-2.45, P=0.62).

CONCLUSION

Overall, there was a 75% relative risk reduction in POI development among patients undergoing laparoscopic gastrointestinal surgery. However, there did not appear to be a significant reduction in all-cause 30-day readmission rate or length of hospitalization. Future studies will need to address which subset of patients undergoing laparoscopic gastrointestinal surgery will benefit most from alvimopan.

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

BACKGROUND

This systematic review summarizes evidence regarding clinical endpoints, early detection, and differential diagnosis of postoperative ileus (POI).

METHODS

Using MEDLINE, EMBASE, Cochrane, and Web-of-Science, we identified 2,084 articles. Risk of bias and level of evidence (LOE) of the included articles were determined, and relevant results were summarized.

RESULTS

Eleven articles were included, most of which with substantial risks of bias. Bowel motility studies revealed that defecation together with solid food tolerance is the most representative clinical endpoint of POI (LOE: 2b); other clinical signs (e.g. bowel sounds, passage of flatus) did not correlate with a full recovery of bowel motility. Inflammatory parameters including interleukin (IL)-6, IL-1, and TNF-α might assist in an early detection of prolonged POI (LOE: 4). Clinical manifestations (e.g. nausea, vomiting, abdominal distension, bowel sounds, flatus) and X-ray examinations provided limited aid to the differential diagnosis of POI, while CT with Gastrografin had the best specificity and sensitivity (both 100%; LOE: 1c).

CONCLUSIONS

Postoperative defecation together with tolerance of solid food intake seems to be the best clinical endpoint of POI. CT has the best differential diagnostic value between POI and other complications. Prospective studies with a high LOE are in great need.

Alvimopan: A cost-effective tool to decrease cystectomy length of stay

INTRODUCTION

We sought to evaluate the cost effectiveness of perioperative use of alvimopan in cystectomy and urinary diversion. A recent randomized controlled trial demonstrated the efficacy of alvimopan in reducing postoperative ileus and length of stay in cystectomy; however, a major limitation was the exclusion of epidural analgesia.

MATERIALS AND METHODS

Eighty-six cystectomy and urinary diversion procedures performed by seven surgeons were analyzed between January 2008 and April 2012. The first 50 patients did not receive alvimopan perioperatively, while the subsequent 36 received a single dose of 12 mg preoperatively and then 12 mg every 12 hours for 15 doses or until discharge.

RESULTS

The groups were equal with respect to age, gender, indication, surgeon, and type of diversion. Patients who received alvimopan experienced a shorter length of stay (LOS) versus those in who did not receive alvimopan (10.5 vs. 8.6 days, p = 0.005, 95% CI 0.6-3.3). Readmission for ileus was low in both alvimopan and control groups (0% and 4.4%, respectively). Costs were significantly lower in the alvimopan group than the control groups (2012 USD 32,443 vs. 40,604 p <0.001). This difference stood up to multivariate analysis with a $7,062 difference in hospital stay.

CONCLUSIONS

Use of alvimopan in the routine perioperative care of our cystectomy and urinary diversion patients has decreased LOS by 1.9 days. Additionally, institution of routine perioperative alvimopan has reduced costs by $7,062 per admission (20% reduction). This demonstrates a real world application of alvimopan at a moderate volume center.

Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients

BACKGROUND

Postoperative ileus is a significant clinical challenge lacking effective management strategies. Ghrelin-receptor stimulation has promotility effects in the upper and lower gastrointestinal tract.

OBJECTIVE

This proof-of-concept, phase 2, randomized study evaluated the safety and efficacy of the ghrelin-receptor agonist ipamorelin in the treatment of postoperative ileus following abdominal surgery (ClinicalTrials.gov NCT00672074).

DESIGN

The design was a multicenter, double-blind, placebo-controlled, clinical trial.

SETTINGS

The settings include hospital inpatients.

PATIENTS

The patients were adults undergoing small and large bowel resection by open or laparoscopic surgery.

INTERVENTION

The intervention was intravenous infusions of 0.03-mg/kg ipamorelin vs placebo twice daily, on postoperative day 1 to 7 or hospital discharge.

MAIN OUTCOME MEASURES

Safety was assessed by monitoring adverse events and laboratory tests. The key efficacy endpoint was time from first dose of study drug to tolerance of a standardized solid meal.

RESULTS

One hundred seventeen patients were enrolled, of whom 114 patients composed the safety and modified intent-to-treat populations. Demographic and disease characteristics were balanced between groups. Overall incidence of any treatment-emergent adverse events was 87.5 % in the ipamorelin group and 94.8 % in placebo group. Median time to first tolerated meal was 25.3 and 32.6 h in the ipamorelin and placebo groups, respectively (p = 0.15).

LIMITATIONS

This proof of concept study was small and enrolled patients with a broad range of underlying conditions.

CONCLUSIONS

Ipamorelin 0.03-mg/kg twice daily for up to 7 days was well tolerated. There were no significant differences between ipamorelin and placebo in the key and secondary efficacy analyses.

Alvimopan reduces length of stay and costs in patients undergoing segmental colonic resections: results from multicenter national administrative database

BACKGROUND

Alvimopan (Entereg), a peripherally acting mu-opioid receptor antagonist, has been shown to expedite recovery of bowel function after colon resection surgery. Most data are available from industry-sponsored trials. This study aims to evaluate the clinical impact of this drug on perioperative outcomes and costs in patients undergoing segmental colonic resection for diverticular disease.

METHODS

A large administrative database maintained by the University Health System Consortium, an alliance of over 200 academic and affiliate hospitals, was queried from 2008 to 2011. International Classification of Diseases, 9th Revision, Clinical Modification codes for segmental colon resection because of diverticular disease were used to identify 2 matched cohorts of adult patients. University Health System Consortium's clinical resource manager was used to access pharmacy data and compare it with patient outcomes.

RESULTS

Five thousand two hundred ninety-nine patients met the above criteria. Four hundred thirty-eight patients received alvimopan and 4,861 did not. Regardless of laparoscopic or open approach, alvimopan significantly improved the postoperative length of stay (4.43 ± 2.02 vs 5.92 ± 3.79, P < .0001), cost (9,974 ± 4,077 vs 11,303 ± 6,968, P < .0001), and intensive care unit admission rate (1.83% vs 7.20%, P < .05), with no significant difference in mortality (.0% vs .19%, P = 1.000), morbidity (5.93% vs 8.39%, P = .08), or 30-day readmission rate (4.40% vs 4.63%, P = .90).

CONCLUSIONS

Alvimopan significantly reduced length of stay, days in the intensive care unit, and hospital cost for patients undergoing colonic segmental resections. Unlike some previously reported studies, we also observed a significant reduction in the length of stay in patients undergoing laparoscopic colectomies who received the drug. Alvimopan may reduce total healthcare costs if used as part of a best care practice model for colon resections.

Cost of practice in a tertiary/quaternary referral center: is it sustainable?

BACKGROUND

Third-party payers are moving toward a bundled care payment system. This means that there will need to be a warranty cost of care-where the cost of complexity and complication rates is built into the bundled payment. The theoretical benefit of this system is that providers with lower complication rates will be able to provide care with lower warranty costs and lower overall costs. This may also result in referring riskier patients to tertiary or quaternary referral centers. Unless the payment model truly covers the higher cost of managing such referred cases, the economic risk may be unsustainable for these centers.

METHODS

We took the last seven patients that were referred by other surgeons as "too high risk" for colectomy at other centers. A contribution margin was calculated using standard Medicare reimbursement rates at our institution and cost of care based on our administrative database. We then recalculated a contribution margin assuming a 3 % reduction in payment for a higher than average readmission rate, like that which will take effect in 2014. Finally, we took into account the cost of any readmissions.

RESULTS

Seven patients with diagnosis related group (DRG) 330 were reviewed with an average age of 66.8 ± 16 years, American Society of Anesthesiologists score 2.3 ± 1.0, body mass index 31.6 ± 9.8 kg/m(2) (range 22-51 kg/m(2)). There was a 57 % readmission rate, 29 % reoperation rate, 10.8 ± 7.7 day average initial length of stay with 14 ± 8.6 day average readmission length of stay. Forty-two percent were discharged to a location other than home. Seventy-one percent of these patients had Medicare insurance. The case mix index was 2.45. Average reimbursement for DRG 330 was $17,084 (based on Medicare data) for our facility in 2012, with the national average being $12,520. The total contribution margin among all cases collectively was -$19,122 ± 13,285 (average per patient -$2,731, range -$21,905-$12,029). Assuming a 3 % reimbursement reduction made the overall contribution margin -$22,122 ± 13,285 (average -$3,244). Including the cost of readmission in the variable cost made the contribution margin -$115,741 ± 16,023 (average -$16,534).

CONCLUSIONS

Care of high-risk patients at tertiary and quaternary referral centers is a very expensive proposition and can lead to financial ruin under the current reimbursement system.

Alvimopan accelerates gastrointestinal recovery after radical cystectomy: a multicenter randomized placebo-controlled trial

BACKGROUND

Radical cystectomy (RC) for bladder cancer is frequently associated with delayed gastrointestinal (GI) recovery that prolongs hospital length of stay (LOS).

OBJECTIVE

To assess the efficacy of alvimopan to accelerate GI recovery after RC.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a randomized double-blind placebo-controlled trial in patients undergoing RC and receiving postoperative intravenous patient-controlled opioid analgesics.

INTERVENTION

Oral alvimopan 12 mg (maximum: 15 inpatient doses) versus placebo.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The two-component primary end point was time to upper (first tolerance of solid food) and lower (first bowel movement) GI recovery (GI-2). Time to discharge order written, postoperative LOS, postoperative ileus (POI)-related morbidity, opioid consumption, and adverse events (AEs) were evaluated. An independent adjudication of cardiovascular AEs was performed.

RESULTS AND LIMITATIONS

Patients were randomized to alvimopan (n=143) or placebo (n=137); 277 patients were included in the modified intention-to-treat population. The alvimopan cohort experienced quicker GI-2 recovery (5.5 vs 6.8 d; hazard ratio: 1.8; p<0.0001), shorter mean LOS (7.4 vs 10.1 d; p=0.0051), and fewer episodes of POI-related morbidity (8.4% vs 29.1%; p<0.001). The incidence of opioid consumption and AEs or serious AEs (SAEs) was comparable except for POI, which was lower in the alvimopan group (AEs: 7% vs 26%; SAEs: 5% vs 20%, respectively). Cardiovascular AEs occurred in 8.4% (alvimopan) and 15.3% (placebo) of patients (p=0.09). Generalizability may be limited due to the exclusion of epidural analgesia and the inclusion of mostly high-volume centers utilizing open laparotomy.

CONCLUSIONS

Alvimopan is a useful addition to a standardized care pathway in patients undergoing RC by accelerating GI recovery and shortening LOS, with a safety profile similar to placebo.

PATIENT SUMMARY

This study examined the effects of alvimopan on bowel recovery in patients undergoing radical cystectomy for bladder cancer. Patients receiving alvimopan experienced quicker bowel recovery and had a shorter hospital stay compared with those who received placebo, with comparable safety.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT00708201.

Physiology, signaling, and pharmacology of opioid receptors and their ligands in the gastrointestinal tract: current concepts and future perspectives

Opioid receptors are widely distributed in the human body and are crucially involved in numerous physiological processes. These include pain signaling in the central and the peripheral nervous system, reproduction, growth, respiration, and immunological response. Opioid receptors additionally play a major role in the gastrointestinal (GI) tract in physiological and pathophysiological conditions. This review discusses the physiology and pharmacology of the opioid system in the GI tract. We additionally focus on GI disorders and malfunctions, where pathophysiology involves the endogenous opioid system, such as opioid-induced bowel dysfunction, opioid-induced constipation or abdominal pain. Based on recent reports in the field of pharmacology and medicinal chemistry, we will also discuss the opportunities of targeting the opioid system, suggesting future treatment options for functional disorders and inflammatory states of the GI tract.

Efficacy and safety of low-dose celecoxib in reducing post-operative paralytic ileus after major abdominal surgery

BACKGROUND

A number of interventions have been used to decrease the incidence of post-operative paralytic ileus. A secondary outcome of a randomized controlled study showed that COX-2 inhibitors decreased the incidence of paralytic ileus. We sought to study a large cohort of patients undergoing major abdominal operations who were treated with a COX-2 inhibitor.

METHODS

This is a retrospective review of prospectively collected data. All eligible patients were given a COX-2 inhibitor--celecoxib 100 mg--twice daily starting on the day of surgery until the seventh day post-operatively or discharge, whichever was earlier. The rate of paralytic ileus was calculated and compared with historical data. Secondary outcome measures were the effect of using COX-2 inhibitors on renal function, electrolytes and haemoglobin, morbidity and leak rates.

RESULTS

Two hundred and fifty-two patients were treated with celecoxib; the control arm consisted of 67 historical patients. Of the 252 patients, we had complete data for 235 patients and ileus in 17 patients (7.23%) compared with 13.4% in the control group (P = 0.05). Subgroup analysis showed ileus in 5.45% of colectomy patients and 6.36% of patients who have had a colectomy and high anterior resection. There was no detriment of measured blood tests. There were leaks in two treated patients, both of whom did not require a laparotomy.

CONCLUSIONS

The use of low-dose COX-2 inhibitor over a short period of time decreases the paralytic ileus rates and does not cause any significant morbidity.

Randomized placebo-controlled study of intravenous methylnaltrexone in postoperative ileus

OBJECTIVE

This phase 2 study evaluated the safety and activity of intravenous methylnaltrexone on the duration of postoperative ileus in patients undergoing segmental colectomy.

METHODS

Adults (aged 18 years or older) with American Society of Anesthesiologists physical status of I, II, or III who underwent segmental colectomy, including partial colectomy, sigmoidectomy, cecectomy, or anterior proctosigmoidectomy, via laparotomy with general anesthesia, received intravenous methylnaltrexone 0.30 mg/kg or placebo every 6 h beginning within 90 min after end of surgery. Treatment continued until 24 h after the patient tolerated solid foods, was discharged, or for 7 d maximum. Efficacy endpoints included measures of gastrointestinal recovery and time to discharge eligibility.

RESULTS

A total of 65 patients (methylnaltrexone, n = 33; placebo, n = 32) were randomized. Mean time to first bowel movement was accelerated by 20 h (p = 0.038) and time to discharge eligibility was accelerated by 33 h (p = 0.049) with methylnaltrexone vs placebo. Opioid use was similar between groups until postoperative day 4, then fluctuated in the placebo group. Methylnaltrexone was generally well tolerated.

CONCLUSIONS

In this study, intravenous methylnaltrexone significantly decreased time to postoperative bowel recovery and eligibility for hospital discharge by ∼1 d, with an adverse event profile similar to placebo. These were two of several exploratory endpoints; not all efficacy endpoints showed a significant difference between methylnaltrexone and placebo. The efficacy results in this trial were not seen in two subsequent large-scale studies.

Improvements in safety and recovery following cystectomy: reassessing the role of pre-operative bowel preparation and interventions to speed return of post-operative bowel function

For radical cystectomy, historical practice trends have favored the use of preoperative bowel preparations to reduce complications, including surgical site infections, ileus, and anastomotic leaks. However, emerging data has questioned this practice. Postoperative cystectomy care also remains in flux, as new pharmacologic agents that may potentiate earlier return of bowel function are studied. We review the current literature with regards to preoperative and postoperative cystectomy bowel management.

Safety and efficacy of ulimorelin administered postoperatively to accelerate recovery of gastrointestinal motility following partial bowel resection: results of two randomized, placebo-controlled phase 3 trials

BACKGROUND

Gastrointestinal recovery is a critical milestone after bowel resection with postoperative ileus resulting in increased risk of complications and prolonged hospitalization.

OBJECTIVE

The aim of this study is to evaluate the efficacy and safety of ulimorelin, a ghrelin receptor agonist given postoperatively in 2 identically designed phase 3 studies (ClinicalTrials.gov NCT01285570 and NCT01296620).

DESIGN

This investigation is designed as a multicenter, double-blind, randomized, parallel-group study.

SETTINGS

This study involves hospital inpatients.

PATIENTS

Adult patients undergoing partial bowel resection were included.

INTERVENTION

Thirty-minute intravenous infusions (160 µg/kg, 480 µg/kg ulimorelin, or placebo) once daily were started within 60 minutes after the end of surgery and ended at the first of the following: primary efficacy end point fulfilled (defined below), hospital discharge, or 7 days treatment.

MAIN OUTCOME MEASURES

The primary efficacy end point was the time from the end of surgery to the composite end point of the later of first bowel movement and tolerance of solid food. Safety was assessed with the use of standard assessments including adverse events and laboratory tests.

RESULTS

Ulimorelin Study of Efficacy and Safety 007, n = 332 patients; Ulimorelin Study of Efficacy and Safety 008, n = 330 patients: in both studies, the primary efficacy end point and the secondary efficacy outcomes, which included postsurgical time to first bowel movement, tolerance of solid food, and discharge eligibility, did not differ significantly among patients treated with either dose of ulimorelin versus placebo. Rates of serious adverse events were comparable across all treatment groups. There was no statistically significant difference from placebo in regard to events of interest, namely nausea, vomiting, ileus as an adverse event, nasogastric tube reinsertion, anastomotic complications, and infections.

LIMITATIONS

A possible limitation is the variance inherent in surgery and comorbidities.

CONCLUSIONS

Although the efficacy of ulimorelin in reducing the duration of postoperative ileus was not demonstrated in these studies, intravenous ulimorelin at doses of 160 µg/kg and 480 µg/kg was generally well tolerated in postcolectomy patients. Similar to other promotility agents, ulimorelin may find an application in other indications better suited to its attributes.

Defining postoperative ileus: results of a systematic review and global survey

BACKGROUND

There is a lack of an internationally accepted standardised clinical definition for postoperative ileus (POI). This has made it difficult to estimate incidence and identify risk factors and has compromised external validity of clinical trials.

AIM

To clarify terminology of POI and propose concise, clinically quantifiable definitions.

METHODS

A systematic review extracted definitions from randomised trials published between 1996 and 2011 investigating POI after abdominal surgery. This was followed by a global survey seeking opinions of those who have published in the field.

RESULTS

Definitions were extracted from 52 identified trials. Responses were received in the survey from 45 of 118 corresponding authors. Data were amalgamated to synthesise the following definitions: postoperative ileus (POI) "interval from surgery until passage of flatus/stool AND tolerance of an oral diet"; prolonged POI "two or more of nausea/vomiting, inability to tolerate oral diet over 24 h, absence of flatus over 24 h, distension, radiologic confirmation occurring on or after day 4 postoperatively without prior resolution of POI"; recurrent POI "two or more of nausea/vomiting, inability to tolerate oral diet over 24 h, absence of flatus over 24 h, distension, radiologic confirmation, occurring after apparent resolution of POI". Concordance of the latter two definitions with survey responses were ≥75 %.

CONCLUSION

We have proposed standardised endpoints for use in future studies to facilitate objective comparison of competing interventions.

The effects of anesthetics on tumor progression

More and more cancer patients receive surgery and chronic pain control. Cell-mediated immunosuppression from surgical stress renders perioperative period a vulnerable period for tumor metastasis. Retrospective studies suggest that regional anesthesia reduces the risk of tumor metastasis and recurrence. This benefit may be due to the attenuation of immunosuppression by regional anesthesia. On the other hand, accumulating evidence points to a direct role of anesthetics in tumor progression. A variety of malignancies exhibit increased activity of voltage-gated sodium channels. Blockade of these channels by local anesthetics may help inhibit tumor progression. Opioids promote angiogenesis, cancer cell proliferation and metastasis. It will be interesting to examine the therapeutic potential of peripheral opioid antagonists against malignancy. Volatile anesthetics are organ-protective against hypoxia, however; this very protective mechanism may lead to tumor growth and poor prognosis. In this review, we examine the direct effects of anesthetics in tumor progression in hope that a thorough understanding will help to select the optimal anesthetic regimens for better outcomes in cancer patients.

A prospective randomized controlled trial of sugared chewing gum on gastrointestinal recovery after major colorectal surgery in patients managed with early enteral feeding

BACKGROUND

A number of small prospective studies with conflicting results have evaluated the effect of sugar-free chewing gum on postoperative GI recovery in patients initially maintained nil per os after major colorectal surgery.

OBJECTIVE

We sought to evaluate the effect of sugared chewing gum in combination with early enteral feeding on recovery of GI function after major colorectal surgery to ascertain any additive effects of this combination.

DESIGN

This was a randomized prospective study.

SETTING

This study was conducted at a single-institution tertiary referral center.

PATIENTS

Patients undergoing major colorectal surgery were included.

INTERVENTIONS

Patients were randomly assigned to sugared chewing gum (Gum) (instructed to chew 3 times daily; 45 minutes each time for 7 days postoperatively) or No Gum after major colorectal surgery.

MAIN OUTCOME MEASURES

The primary outcome measured was time to tolerating low residue diet without emesis for 24 hours. The secondary outcomes measured were time to flatus, time to bowel movement, postoperative hospital stay, postoperative pain, nausea, and appetite.

RESULTS

One hundred fourteen patients (60 No Gum; 54 Gum) were included in our analysis after randomization. There was no significant difference in time to tolerating a low-residue diet, time to flatus, time to bowel movement, length of postoperative hospital stay, postoperative complications, postoperative pain, nausea, or appetite between patients assigned to Gum or No Gum. There was an increased incidence of bloating, indigestion, and eructation in the Gum group (13%) in comparison with the No Gum group (2%) (p = 0.03).

LIMITATIONS

Study subjects and investigators were not blinded. Multiple types of operations may cause intergroup variability.

CONCLUSIONS

There does not appear to be any benefit to sugared chewing gum in comparison with no gum in patients undergoing major colorectal surgery managed with early feeding in the postoperative period. There may be increased incidence of bloating, indigestion, and eructation, possibly related to swallowed air during gum chewing.