A Shared Decision Approach to Chronic Abdominal Pain Based on Cine-MRI: A Prospective Cohort Study

Morphological features and molecular mechanisms in peritoneal adhesions from patients with chronic abdominal postoperative pain

BACKGROUND

Chronic abdominal pain affects 10-20% of all patients following abdominal surgery, with adhesions as a predominant cause. However, the biological mechanisms underlying adhesion-related pain are not fully elucidated. This study aimed to establish the morphological and molecular phenotype of adhesions in patients with and without chronic postoperative abdominal pain.

METHODS

In this case-control study, biopsies of adhesions were obtained from patients with chronic postoperative abdominal pain (related to adhesions on cineMRI) and controls without pain, from two tertiary care and one secondary care hospital. Quantitative histological analysis of haematoxylin and eosin-stained sections was performed, while immunohistochemical (IHC) markers for nerve tissue (S100, calretinin and synaptophysin) were quantified through image analysis. RNA expression of genes (TRPV1, BDNF, TAC1, TACR1, NGF) was measured using real time quantitative polymerase chain reaction (RT-qPCR). Controls were matched to cases by sex, age, and prior surgery, accepting small variations due to patient availability. An independent two-sided t-test was used to detect differences in IHC and RT-qPCR analysis between groups.

FINDINGS

Adhesions from 31 patients with pain were compared to those from 31 patients without pain, consisting of 48% connective tissue and 41% adipose tissue. Immunohistochemical analysis revealed increased nerve tissue in patients with pain (S100: median 597 ppm (range 92.2-3223.2 ppm) vs 151 ppm (range 15.2-1683.8 ppm) p < 0.001; calretinin: median 463 ppm (range 72.7-2996.5 ppm) vs 275 ppm (range 35.3-3194.8 ppm) p = 0.040). NGF showed a higher mRNA expression in adhesions from patients with pain compared to controls (p = 0.012).

INTERPRETATION

This study suggests a distinct morphological and molecular phenotype of adhesions in patients experiencing adhesion-related pain, providing insights into underlying mechanisms.

FUNDING

Veni grant from The Dutch Governmental Organisation for Health Research and Development (ZonMw grant number 91619035).

Shared decision-making improving efficacy in diarrhoea-dominant irritable bowel syndrome in Chinese outpatient setting: protocol of a prospective, randomised controlled trial

INTRODUCTION

Diarrhoea-dominant irritable bowel syndrome (IBS-D) is a disorder with multiple pathogenesis; many people with IBS-D may have psychosocial issues which can make assessment and treatment more difficult. Routine treatment procedure might not always achieve the desired outcome. Therefore, patients may not be satisfied with the conventional experience and would like to be more involved in clinical decision-making. A shared decision-making (SDM) model, that requires patient participation, has been demonstrated to have a powerful effect on the diagnosis and treatment of other diseases, which improves patients' compliance, satisfaction, thus refining the clinical outcome. However, there is no corresponding evidence in IBS-D. Herein, we hope to verify the effect of SDM through clinical studies, and we anticipate that SDM can improve the therapeutic effect in patients with IBS-D.

METHODS

The study is a prospective, randomised, single-centre trial. 166 IBS-D outpatients who attend Peking Union Medical College Hospital will be allocated into routine treatment group and SDM group. The primary endpoint is the severity of bowel symptoms, measured by the IBS symptom severity scale. Secondary endpoints include impact of disease and quality of life, negative psychology and the evaluation of diagnosis and treatment process.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the research ethics committee of Peking Union Medical College Hospital (I-23PJ470). This protocol has been approved by Chinese Clinical Trial Register (ChiCTR2300073681) in July 2023. The results of this trial will be published in an open-access way and disseminated among gastrointestinal physicians.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Register (ChiCTR2300073681).

Quantifiable Measures of Abdominal Wall Motion for Quality Assessment of Cine-MRI Slices in Detection of Abdominal Adhesions

Abdominal adhesions present a diagnostic challenge, and classic imaging modalities can miss their presence. Cine-MRI, which records visceral sliding during patient-controlled breathing, has proven useful in detecting and mapping adhesions. However, patient movements can affect the accuracy of these images, despite there being no standardized algorithm for defining sufficiently high-quality images. This study aims to develop a biomarker for patient movements and determine which patient-related factors influence movement during cine-MRI. Included patients underwent cine-MRI to detect adhesions for chronic abdominal complaints, data were collected from electronic patient files and radiologic reports. Ninety slices of cine-MRI were assessed for quality, using a five-point scale to quantify amplitude, frequency, and slope, from which an image-processing algorithm was developed. The biomarkers closely correlated with qualitative assessments, with an amplitude of 6.5 mm used to distinguish between sufficient and insufficient-quality slices. In multivariable analysis, the amplitude of movement was influenced by age, sex, length, and the presence of a stoma. Unfortunately, no factor was changeable. Strategies for mitigating their impact may be challenging. This study highlights the utility of the developed biomarker in evaluating image quality and providing useful feedback for clinicians. Future studies could improve diagnostic quality by implementing automated quality criteria during cine-MRI.

A Randomized Double-Blind Controlled Proof-of-Concept Study of Alanyl-Glutamine for Reduction of Post-Myomectomy Adhesions

STUDY OBJECTIVE

To test the hypothesis that intraperitoneal instillation of a single bolus dose of l-alanyl-l-glutamine (AG) will reduce the incidence, extent and/or severity of adhesions following myomectomy and establish preliminary safety and tolerability of AG in humans.

DESIGN

Phase 1,2 Randomized, double-blind, placebo-controlled study (DBRCT).

SETTING

Tertiary care gynecology surgical centre.

PATIENTS

Thirty-eight women who underwent myomectomies by laparoscopy (N = 38; AG-19 vs Placebo-19) or laparotomy (N = 10; AG-5 vs Placebo-5) with a scheduled second-look laparoscopy (SLL) 6-8 weeks later. Thirty-two patients in the laparoscopy arm completed SLL.

INTERVENTIONS

Bolus dose of AG or normal saline solution control (0.9% NaCl) administered intraperitoneally immediately prior to suture closure of the laparoscopic ports. The average dose was 170 mL of AG or control based on a dosing scheme of 1 g/kg bodyweight.

MEASUREMENTS

Digital recordings obtained for all procedures. The primary endpoint was reduction in the incidence, severity and extent of post-operative adhesions analyzed by intention-to-treat (ITT) approach. Three independent, blinded reviewers evaluated all operative video recordings to assess presence of adhesions. Post-hoc analysis assessed presence or absence of adhesions in the peritoneal cavity. Secondary endpoints assessed safety and tolerability of AG.

MAIN RESULTS

Administration of AG reduced the incidence, severity and/or extent of post-operative adhesions (p = 0.046). The presence of adhesions in the AG group was lower than in the Control group (p = 0.041). Adhesion improvement was achieved in 15 of 15 (100%) in the AG group versus 5 of 17 (29.6%) in the placebo group. No serious adverse events were reported. No differences in safety parameters were observed.

CONCLUSIONS

Intraperitoneal l-alanyl-l-glutamine reduced adhesion formation in all patients following laparoscopic myomectomy. Complete absence of adhesions was achieved at all abdominal sites in 93% of patients. Results confirm AG's known effects on cellular mechanisms of adhesiogenesis and lay the foundation for new adhesion prophylaxis research and treatment.

Inter- and Intra-Observer Variability and the Effect of Experience in Cine-MRI for Adhesion Detection

Cine-MRI for adhesion detection is a promising novel modality that can help the large group of patients developing pain after abdominal surgery. Few studies into its diagnostic accuracy are available, and none address observer variability. This retrospective study explores the inter- and intra-observer variability, diagnostic accuracy, and the effect of experience. A total of 15 observers with a variety of experience reviewed 61 sagittal cine-MRI slices, placing box annotations with a confidence score at locations suspect for adhesions. Five observers reviewed the slices again one year later. Inter- and intra-observer variability are quantified using Fleiss’ (inter) and Cohen’s (intra) κ and percentage agreement. Diagnostic accuracy is quantified with receiver operating characteristic (ROC) analysis based on a consensus standard. Inter-observer Fleiss’ κ values range from 0.04 to 0.34, showing poor to fair agreement. High general and cine-MRI experience led to significantly (p < 0.001) better agreement among observers. The intra-observer results show Cohen’s κ values between 0.37 and 0.53 for all observers, except one with a low κ of −0.11. Group AUC scores lie between 0.66 and 0.72, with individual observers reaching 0.78. This study confirms that cine-MRI can diagnose adhesions, with respect to a radiologist consensus panel and shows that experience improves reading cine-MRI. Observers without specific experience adapt to this modality quickly after a short online tutorial. Observer agreement is fair at best and area under the receiver operating characteristic curve (AUC) scores leave room for improvement. Consistently interpreting this novel modality needs further research, for instance, by developing reporting guidelines or artificial intelligence-based methods.

Elective adhesiolysis for chronic abdominal pain reduces long-term risk of adhesive small bowel obstruction

BACKGROUND

Selected patients with adhesion-related chronic abdominal pain can be treated effectively by adhesiolysis with the application of adhesion barriers. These patients might also have an increased risk to develop adhesive small bowel obstruction (ASBO). It is unknown how frequently these patients develop ASBO, and how elective adhesiolysis for pain impacts the risk of ASBO.

METHODS

Patients with adhesion-related chronic pain were included in this cohort study with long-term follow-up. The diagnosis of adhesions was confirmed using CineMRI. The decision for operative treatment of adhesions was made by shared agreement based on the correlation of complaints with CineMRI findings. The primary outcome was the 5-years incidence of readmission for ASBO. Incidence was compared between patients with elective adhesiolysis and those treated non-operatively and between patients with and without previous ASBO. Univariable and multivariable Cox regression analysis was performed to identify predictive factors for ASBO. Secondary outcomes included reoperation for ASBO and self-reported pain and other abdominal symptoms.

RESULTS

A total of 122 patients were included, 69 patients underwent elective adhesiolysis. Thirty patients in both groups had previous episodes of ASBO in history. During 5-year follow-up, the readmission rate for ASBO was 6.5% after elective adhesiolysis compared to 26.9% after non-operative treatment (p = 0.012). These percentages were 13.3% compared to 40% in the subgroup of patients with previous episodes of ASBO (p = 0.039). In multivariable analysis, elective adhesiolysis was associated with a decreased risk of readmission for ASBO with an odds ratio of 0.21 (95% CI 0.07-0.65), the risk was increased in patients with previous episodes with a odds ratio of 19.2 (95% CI 2.5-144.4). There was no difference between the groups in the prevalence of self-reported abdominal pain. However, in surgically treated patients the impact of pain on daily activities was lower, and the incidence of other symptoms was lower.

CONCLUSION

More than one in four patients with chronic adhesion-related pain develop episodes of ASBO when treated non-operatively. Elective adhesiolysis reduces the incidence of ASBO in patients with chronic adhesion-related symptoms, both in patients with and without previous episodes of ASBO in history. Trial registration The study was registered at Clinicaltrials.gov under NCT01236625.

Analgesia in patients with adhesion-related chronic abdominal and pelvic pain after surgery: a systematic review

BACKGROUND AND OBJECTIVE

Adhesions are the most common cause of chronic abdominal pain after surgery. Surgical adhesiolysis can relieve symptoms in selected patients, but many require other treatments. The aim of this study is to evaluate analgesic treatments other than abdominal surgery in chronic pain related to adhesions.

DATABASE AND DATA TREATMENT

A search was conducted in PubMed, Embase, and Central. Studies with patients suffering from chronic postoperative pain related to adhesions and undergoing all types' analgesic treatment were included. The primary outcome was the number of patients who improved in pain at long-term follow-up (at least 1 year). Secondary outcomes included improvement in pain at 3 months follow-up, quality of life, and physical functioning.

RESULTS

Searches identified 3022 citations. Four studies were included, one trial, one cohort study, and two case reports. The primary outcome was not reported. In a small trial (n = 18) pregabalin tended to have a benefit over placebo improving pain at 3 months. In the cohort study, 17 patients with chronic pelvic pain underwent a trial of sacral nerve stimulation. Eight patients who responded positively received an implanted device for continuous modulation, reporting sustainable improvement during follow-up (range: 6-36 months). One case report described improved pain at 6 months with trans-abdominis plane stimulation. The second report described improvement of physical function with manual therapy at long-term follow-up.

CONCLUSIONS

Low level of evidence is available regarding analgesic treatments of chronic abdominal and pelvic pain related to adhesions. The benefit of pregabalin is doubtful; nerve modulation is promising in a selected group.HighlightsAdhesions are a frequent cause of chronic abdominal and pelvic pain after surgery.Many patients are not good candidates for surgery (Adhesiolysis) or have relapses of pain.There is an important knowledge gap regarding non-surgical analgesic treatment.Analgesia in adhesion-related chronic abdominal pain after surgery.

The Future of Adhesion Prophylaxis Trials in Abdominal Surgery: An Expert Global Consensus

Postoperative adhesions represent a frequent complication of abdominal surgery. Adhesions can result from infection, ischemia, and foreign body reaction, but commonly develop after any surgical procedure. The morbidity caused by adhesions affects quality of life and, therefore, it is paramount to continue to raise awareness and scientific recognition of the burden of adhesions in healthcare and clinical research. This 2021 Global Expert Consensus Group worked together to produce consented statements to guide future clinical research trials and advise regulatory authorities. It is critical to harmonize the expectations of research, to both develop and bring to market improved anti-adhesion therapies, with the ultimate, shared goal of improved patient outcomes.

A Randomized Controlled Trial of Thermo-Sensitive Sol-Gel Anti-Adhesion Agent after Gynecologic Surgery

Postoperative abdominal adhesions can lead to several adverse consequences such as pelvic pain, bowel obstruction, and infertility. We aimed to explore the anti-adhesion efficacy and safety of a thermo-sensitive sol-gel agent in patients who receive abdominopelvic surgery for benign gynecologic disease. This study was a randomized, controlled, single-blind clinical trial of women undergoing benign gynecologic surgery between January 2017 and December 2017. The patients were randomly assigned to three groups with a 1:1:1 ratio: experimental group (received the thermo-sensitive sol-gel agent), control group (untreated), and comparator group (received 4% icodextrin). Patients were followed for 4 weeks postoperatively, and efficacy was evaluated by performing the visceral slide test to identify adhesion formation. In total, 183 patients were enrolled in the study, and 178 (97.3%) completed the trial. The incidence rate of abdominal adhesion formation was significantly lower in the experimental group than in the control group (7.9% vs. 21.1%, p = 0.040); however, it was similar between the experimental and comparator groups (7.9% vs. 13.8%. p = 0.299). At 4 weeks, no differences in adhesion-related symptoms were observed between the experimental and control groups. Adverse events were mostly mild and did not differ significantly among the three groups (p = 0.375). In conclusion, use of a thermo-sensitive sol-gel agent was safe and effective to prevent abdominal adhesions after benign gynecologic surgeries.

Adhesion-related readmissions after open and laparoscopic surgery: a retrospective cohort study (SCAR update)

BACKGROUND

Adhesions are the most common driver of long-term morbidity after abdominal surgery. Although laparoscopy can reduce adhesion formation, the effect of minimally invasive surgery on long-term adhesion-related morbidity remains unknown. We aimed to assess the impact of laparoscopy on adhesion-related readmissions in a population-based cohort.

METHODS

We did a retrospective cohort study of patients of any age who had abdominal or pelvic surgery done using laparoscopic or open approaches between June 1, 2009, and June 30, 2011, using validated population data from the Scottish National Health Service. All patients who had surgery were followed up until Dec 31, 2017. The primary outcome measure was the incidence of hospital readmissions directly related to adhesions in the laparoscopic and open surgery cohorts at 5 years. Readmissions were categorised as directly related to adhesions, possibly related to adhesions, and readmissions for an operation that was potentially complicated by adhesions. We did subgroup analyses of readmissions by anatomical site of surgery and used Kaplan-Meier analyses to assess differences in survival across subgroups. We used multivariable Cox-regression analysis to determine whether surgical approach was an independent and significant risk factor for adhesion-related readmissions.

FINDINGS

Between June 1, 2009, and June 30, 2011, 72 270 patients had an index abdominal or pelvic surgery, of whom 21 519 (29·8%) had laparoscopic index surgery and 50 751 (70·2%) had open surgery. Of the 72 270 patients who had surgery, 2527 patients (3·5%) were readmitted within 5 years of surgery for disorders directly related to adhesions, 12 687 (17·6%) for disorders possibly related to adhesions, and 9436 (13·1%) for operations potentially complicated by adhesions. Of the 21 519 patients who had laparoscopic surgery, 359 (1·7% [95% CI 1·5-1·9]) were readmitted for disorders directly related to adhesions compared with 2168 (4·3% [4·1-4·5]) of 50 751 patients in the open surgery cohort (p<0·0001). 3443 (16·0% [15·6-16·4]) of 21 519 patients in the laparoscopic surgery cohort were readmitted for disorders possibly related to adhesions compared with 9244 (18·2% [17·8-18·6]) of 50 751 patients in the open surgery cohort (p<0·005). In multivariate analyses, laparoscopy reduced the risk of directly related readmissions by 32% (hazard ratio [HR] 0·68, 95% CI 0·60-0·77), and of possibly related readmissions by 11% (HR 0·89, 0·85-0·94) compared with open surgery. Procedure type, malignancy, sex, and age were also independently associated with risk of adhesion-related readmissions.

INTERPRETATION

Laparoscopic surgery reduces the incidence of adhesion-related readmissions. However, the overall burden of readmissions associated with adhesions remains high. With further increases in the use of laparoscopic surgery expected in the future, the effect at the population level might become larger. Further steps remain necessary to reduce the incidence of adhesion-related postsurgical complications.

FUNDING

Dutch Adhesion Group and Nordic Pharma.