Clinical adhesion score (CLAS): development of a novel clinical score for adhesion-related complications in abdominal and pelvic surgery

Prevention of post-operative adhesions: Model development and pilot outcomes of human placental stem cell-based interventions

BACKGROUND

Abdominal adhesions are the most common surgical complication and without reliable prophylactics. This study presents a novel rat model for abdominal adhesions and reports pilot results of human placental stem cell (hPSC)-based therapies.

METHODS

Forty-four (n = 44) male Sprague-Dawley rats (250-350 g) were used in the experiment. Of these, thirty-eight (n = 38) were included in a preliminary data set to determine a minimum treatment effect. Adhesions were created in a reproducible model to the abdominal wall and between organs. Experimental groups included the control group (Model No Treatment, MNT), Plasmalyte A (Media Alone, MA, 10 mL), hPSC (5 × 106 cells/10 mL Plasmalyte A), hPSC-CM (hPSC secretome, conditioned media) in 10 mL Plasmalyte A, Seprafilm™ (Baxter, Deerfield, IL), and sham animals (laparotomy only). Treatments were inserted intraperitoneally (IP) and the study period was 14 days post-operation. Results are reported as the difference between means of an index statistic (AIS, Animal Index Score) and compared by ANOVA with pairwise comparison.

RESULTS

The overall mean AIS was 23 (SD 6.16) for the MNT group with an average of 75% of ischemic buttons involved in abdominal adhesions. Treatment groups MA (mean overall AIS 17.33 SD 6.4), hPSC (mean overall AIS 13.86 SD 5.01), hPSC-CM (mean overall AIS 13.13 SD 6.15), and Seprafilm (mean overall AIS 13.43 SD 9.11) generated effect sizes of 5.67, 9.14, 9.87, and 9.57 decrease in mean overall AIS, respectively, versus the MNT.

DISCUSSION

The presented rat model and scoring system represent the clinical adhesion disease process. hPSC-based interventions significantly reduce abdominal adhesions in this pilot dataset.

Reproducibility and predictive value of three grading systems for intraoperative adverse events in a cohort of abdominal surgery

INTRODUCTION

Intraoperative adverse events (iAEs) are increasingly recognized for their impact on patient outcomes. The Kaafarani classification and Surgical Apgar Score (SAS) were developed to assess the intraoperative course; however, both have their drawbacks. ClassIntra was validated for iAEs of any origin. This study compares the Kaafarani and SAS to ClassIntra considering predictive value and interrater reliability in a cohort of abdominal surgery to support implementation of a classification in clinical practice.

METHODS

The authors made use of the LAParotomy or LAParoscopy and ADhesiolysis (LAPAD) study database of elective abdominal surgery. Detailed descriptions on iAEs were collected in real-time by a researcher. For the current research aim, all iAEs were graded according ClassIntra, Kaafarani, and SAS (score ≤4). The predictive value was assessed using univariable and multivariable linear regression and the area under the receiver operating curve (AUROC). Two teams graded ClassIntra and Kaafarani to assess the interrater reliability using Cohen's Kappa.

RESULTS

A total of 755 surgeries were included, in which 335 (44%) iAEs were graded according to ClassIntra, 228 (30%) to Kaafarani, and 130 (20%) to SAS. All classifications were significantly correlated to postoperative complications, with an AUROC of 0.67 (95% CI: 0.62-0.72), 0.64 (0.59-0.70), and 0.71 (0.56-0.76), respectively. For the secondary endpoint, the interrater reliability of ClassIntra with κ 0.87 (95% CI: 0.84-0.90) and Kaafarani 0.90 (95% CI: 0.87-0.93) was both strong.

CONCLUSION

ClassIntra, Kaafarani, and SAS can be used for reporting of iAEs in abdominal surgery with good predictive value for postoperative complications, with strong reliability. ClassIntra, compared with Kaafarani and SAS, included the most iAEs and has the most comprehensive definition suitable for uniform reporting of iAEs in clinical practice and research.

Perspectives in adhesion prevention in gynaecological surgery

Adhesions are a frequent, clinically relevant, and often costly complication of surgery that can develop in any body location regardless of the type of surgical procedure. Adhesions result from surgical trauma inducing inflammatory and coagulation processes and to date cannot be entirely prevented. However, the extent of adhesion formation can be reduced by using good surgical technique and the use of anti-inflammatory drugs, haemostats, and barrier agents. Strategies are needed in the short-, medium- and longer-term to improve the prevention of adhesions. In the short-term, efforts are needed to increase the awareness amongst surgeons and patients about the potential risks and burden of surgically induced adhesions. To aid this in the medium- term, a risk score to identify patients at high risk of adhesion formation is being developed and validated. Furthermore, available potentially preventive measures need to be highlighted. Both clinical and health economic evaluations need to be undertaken to support the broad adoption of such measures. In the longer- term, a greater understanding of the pathogenic processes leading to the formation of adhesions is needed to help identify effective, future treatments to reliably prevent adhesions from forming and lyse existing ones.

Appraisal of Intraoperative Adverse Events to Improve Postoperative Care

Background: Intraoperative adverse events (iAEs) are associated with adverse postoperative outcomes and cause a significant healthcare burden. However, a critical appraisal of iAEs is lacking. Considering the details of iAEs could benefit postoperative care. We comprehensively analyzed iAEs in a large series including all types of operations and their relation to postoperative complications. Methods: All patients enrolled in the multicenter ClassIntra® validation study (NCT03009929) were included in this analysis. The surgical and anesthesia team prospectively recorded all iAEs. Two researchers, blinded to each other’s ratings, appraised all recorded iAEs according to their origin into four categories: surgery, anesthesia, organization, or other, including subcategories such as organ injury, arrhythmia, or instrument failure. They further descriptively analyzed subcategories of all iAEs. Postoperative complications were assessed using the Comprehensive Complication Index (CCI®), a weighted sum of all postoperative complications according to the Clavien–Dindo classification. The association of iAE origins in addition to the severity grade of ClassIntra® on CCI® was assessed with a multivariable mixed-effects generalized linear regression analysis. Results: Of 2520 included patients, 778 iAEs were recorded in 610 patients. The origin was surgical in 420 (54%), anesthesia in 283 (36%), organizational in 34 (4%), and other in 41 (5%) events. Bleeding (n = 217, 28%), hypotension (n = 118, 15%), and organ injury (n = 98, 13%) were the three most frequent subcategories in surgery and anesthesia, respectively. In the multivariable mixed-effect analysis, no significant association between the origin and CCI® was observed. Conclusion: Analyzing the type and origin of an iAE offers individualized and contextualized information. This detailed descriptive information can be used for targeted surveillance of intra- and postoperative care, even though the overall predictive value for postoperative events was not improved by adding the origin in addition to the severity grade.

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.

Classification of intraoperative adverse events in visceral surgery

BACKGROUND

Intraoperative adverse events (iAEs) are frequent in visceral surgery, but severity and related postoperative outcome are poorly investigated. A novel classification of intraoperative adverse events, ClassIntra, includes surgical and anesthesiologic intraoperative adverse events using 5 severity grades and showed a high criterion and construct validity across all surgical disciplines. ClassIntra was studied for reproducibility in a prespecified group of patients undergoing visceral surgery.

METHODS

iAEs were recorded in all patients enrolled in the ClassIntra validation study (NCT03009929). Postoperative complications were assessed daily according to the Clavien-Dindo classification. Results of the visceral group were compared with those of the non-visceral group and the full cohort. The risk-adjusted association between most severe intra and postoperative complications was investigated in a multivariable proportional odds model. Second, risk-adjusted association between ClassIntra grade and Comprehensive Complication Index, and postoperative length of stay was investigated.

RESULTS

In total, 1,270 out of 2,520 patients (50%) underwent visceral surgery. Compared with the nonvisceral group and full cohort, more intraoperative (337/1270 [27%] vs 273/1250 [22%] vs 610/2520 [24%] patients) and postoperative complications (457/1270 [36%] vs 381/1250 [30%] vs 838/2520 [33%] patients) occurred. The risk for a more severe postoperative complication increased with each ClassIntra grade (odds ratio [95% confidence interval] I vs 0 1.10 [0.73 to 1.66], II vs 0 1.69 [1.10 to 2.60], III vs 0 2.31 [1.21 to 4.41], IV vs 0 2.35 [0.69 to 8.06]). Accordingly, CCI and postoperative length of stay increased with each ClassIntra grade in the visceral group, comparable with the nonvisceral and full cohort.

CONCLUSION

Consistent results for the association of intraoperative adverse events and patient outcomes render ClassIntra a valuable instrument in visceral 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.

Safety, efficacy, and operability of a newly developed absorbable adhesion barrier (GM142) in patients with primary rectal cancer scheduled for diverting ileostomy during laparoscopic surgery: Randomized controlled trial

Aim

The aim of this study was to compare the outcomes of GM142, a newly developed gelatin film with a concave and convex structure to a commercially available conventional film, hyaluronate‐carboxymethylcellulose.

Methods

Patients with primary rectal cancer who were scheduled for diverting ileostomy during laparoscopic surgery were eligible for this study. Patients were randomized before surgery and an antiadhesion film was applied under the umbilical incision. The primary outcome was the incidence of adhesion under the midline incision confirmed by second‐look surgery for diverting ileostomy closure. The secondary outcomes were the adhesion severity score, the extent of adhesion score, the presence of intestinal obstruction, and the success of all patching.

Results

A total of 146 patients were enrolled. A total of 123 patients were included in the full analysis set. The primary outcome of “no adhesion” was observed in 66.1% in the GM142 group and 55.7% in the conventional film group. The noninferiority of GM142 to conventional film was confirmed (P = .0005). The secondary outcomes were similar between the groups. For the safety evaluation, there were no safety concerns regarding allergic reactions to gelatin or increased gelatin‐specific IgE antibody titers.

Conclusions

The noninferiority of GM142 to conventional film was shown. GM142 showed no major safety issues. The clinical safety profiles of GM142 suggested certain physiological benefits of the gelatin film as an adhesion barrier.

A review: progress in preventing tissue adhesions from a biomaterial perspective

Postoperative adhesions (POA) are one of the main problems suffered by patients and are a common complaint. It is considered to be closely associated with the healing mechanism of damaged tissues. Tissue adhesions accompany other symptoms such as inflammation, pain, and even dyskinesia under certain conditions, compromising the patients' quality of life. On the other hand, common treatments involve high costs, re-surgery or long-term hospital stays. Therefore, alternative approaches need to be formulated so that aforementioned problems can be resolved. To this end, a review of recent advances in this context is imperative. In this review, we have highlighted the mechanism of adhesion formation, advances in common therapeutic approaches, and prospective treatments in preventing tissue adhesions. Based on the literature, it can be determined that the disadvantages of available commercial products in the treatment of tissue adhesion have led researchers to utilize alternative methods for designing anti-adhesive products with different structures such as electrospun fibrous mats, hydrogels, and nanospheres. These studies are on the fast track in producing optimal anti-adhesion materials. We hope that this article can attract attention by showing various mechanisms and solutions involved in adhesion problems and inspire the further development of anti-adhesion biomaterials.