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

Neutrophil Extracellular Traps-Inhibiting and Fouling-Resistant Polysulfoxides Potently Prevent Postoperative Adhesion, Tumor Recurrence, and Metastasis

Peritoneal metastasis (PM) is considered one of the most dreaded forms of cancer metastases for both patients and physicians. Aggressive cytoreductive surgery (CRS) is the primary treatment for peritoneal metastasis. Unfortunately, this intensive treatment frequently causes clinical complications, such as postoperative recurrence, metastasis, and adhesion formation. Emerging evidence suggests that neutrophil extracellular traps (NETs) released by inflammatory neutrophils contribute to these complications. Effective NET-targeting strategies thus show considerable potential in counteracting these complications but remain challenging. Here, one type of sulfoxide-containing homopolymer, PMeSEA, with potent fouling-resistant and NET-inhibiting capabilities, is synthesized and screened. Hydrating sulfoxide groups endow PMeSEA with superior nonfouling ability, significantly inhibiting protein/cell adhesion. Besides, the polysulfoxides can be selectively oxidized by ClO- which is required to stabilize the NETs rather than H2O2, and ClO- scavenging effectively inhibits NETs formation without disturbing redox homeostasis in tumor cells and quiescent neutrophils. As a result, PMeSEA potently prevents postoperative adhesions, significantly suppresses peritoneal metastasis, and shows synergetic antitumor activity with chemotherapeutic 5-Fluorouracil. Moreover, coupling CRS with PMeSEA potently inhibits CRS-induced tumor metastatic relapse and postoperative adhesions. Notably, PMeSEA exhibits low in vivo acute and subacute toxicities, implying significant potential for clinical postoperative adjuvant treatment.

Does the presence of abdominal wall adhesions make gynecologic robotic surgery difficult?

This study aimed to assess the status of abdominal wall adhesions resulting from prior surgeries and their impact on the outcomes of robotic surgery. We retrospectively reviewed clinical information, surgical outcomes, and the status of abdominal wall adhesions in patients who underwent gynecologic robotic surgery at Yamanashi Central Hospital, between April 2018 and March 2023. Abdominal wall adhesions were classified into seven locations and their presence was assessed at each site. Among the 768 cases examined, 196 showed the presence of abdominal wall adhesions. Notably, patients with a history of abdominal surgery exhibited a significantly higher incidence of abdominal wall adhesions than those without such surgical history, although no significant difference was observed in the frequency of adhesions in the upper left abdomen. Patients with a history of gynecologic, gastrointestinal, or biliopancreatic surgeries were more likely to have adhesions at the umbilicus or upper abdomen sites where trocars are typically inserted during robotic surgery. Although cases with abdominal wall adhesions experienced longer operative times than those without, there was no significant difference in estimated blood loss. In 13 cases (1.7%), adjustments in trocar placement were necessary due to abdominal wall adhesions, although none of the cases required conversion to open or conventional laparoscopic surgery. Abdominal wall adhesions pose challenges to minimally invasive procedures, emphasizing the importance of predicting these adhesions based on a patient's surgical history to safely perform robotic surgery. These results suggest that the robot's flexibility proves effective in managing abdominal wall adhesions.

What are the short- and long-term abdominal consequences of an omentectomy? A systematic review

This review provides an overview regarding the abdominal effects of an omentectomy, with or without extra-peritoneal reconstructions. In general, reported complication rates were low. Short-term complications involved ileus, bowel stenosis, abdominal abscess and sepsis (range 0.0%-23%). Donor-site hernia was mainly reported as long-term complication (up to 32%) and negligible gastrointestinal complications were observed. However, the level of evidence and methodological quality are quite low with a maximum of 8.5 years follow-up.

Hemoadhican-Based Bioabsorbable Hydrogel for Preventing Postoperative Adhesions

Postoperative peritoneal adhesions are a prevalent clinical issue following abdominal and pelvic surgery, frequently resulting in heightened personal and societal health burdens. Traditional biomedical barriers offer limited benefits because of practical challenges for doctors and their incompatibility with laparoscopic surgery. Hydrogel materials, represented by hyaluronic acid gels, are receiving increasing attention. However, existing antiadhesive gels still have limited effectiveness or carry the risk of complications in clinical applications. Herein, we developed a novel hydrogel using polysaccharide hemoadhican (HD) as the base material and polyethylene glycol diglycidyl ether (PEGDE) as the cross-linking agent. The HD hydrogels exhibit appropriate mechanical properties, injectability, and excellent cytocompatibility. We demonstrate resistance to protein adsorption and L929 fibroblast cell adhesion to the HD hydrogel. The biodegradability and efficacy against peritoneal adhesion are further evaluated in C57BL/6 mice. Our results suggest a potential strategy for anti-postoperative tissue adhesion barrier biomaterials.

Inhibition of chemokine receptor CXCR2 attenuates postoperative peritoneal adhesion formation

BACKGROUND

Postoperative peritoneal adhesions remain a problem after general and gynecological surgery.

METHODS

Hematoxylin and eosin and Masson's trichrome staining of ischemic buttons were performed 6, 12, 24 hours, and 7 days after button induction. Scanning electron microscopy, ribonucleic acid sequencing, quantitative real-time polymerase chain reaction, immunohistochemical staining, and flow cytometry were used to elucidate the pathophysiology of postoperative peritoneal adhesions.

RESULTS

The results showed that thickening of the peritoneum and abscission of mesothelial cells and collagen fibers increased significantly on the surface of the "button" in the control groups at 24 hours postoperatively. Scanning electron microscopy revealed a large number of granulocytes on the button surface in the control group at 24 hours. Ribonucleic acid sequencing and quantitative real-time polymerase chain reaction also revealed that CXCR2 expression was significantly upregulated. In addition, danirixin, a CXCR2 inhibitor, reduced abdominal adhesion in the injured area by inhibiting the infiltration of inflammatory cells and collagen production. Immunohistochemical staining showed decreased expression of CXCR2 in the adhesion area 7 days after surgery in the treatment group. Flow cytometry showed a significantly decreased neutrophil ratio in the treatment group compared with that in the control group 24 hours after the operation.

CONCLUSIONS

Inflammation plays an important role in the early stages of postoperative peritoneal adhesion formation, whereas collagen fibers and angiogenesis play important roles in the late stages. The CXCL2-CXCL3-CXCR2 signaling axis is an important link in the mechanism of postoperative peritoneal adhesion formation, and the application of CXCR2 inhibitors can alleviate the formation of postoperative peritoneal adhesions.

A Graphene Composite Film Based Wearable Far-Infrared Therapy Apparatus (GRAFT) for Effective Prevention of Postoperative Peritoneal Adhesion

Postoperative peritoneal adhesion (PPA) is the most frequent complication after abdominal surgery. Current anti-adhesion strategies largely rely on the use of physical separating barriers creating an interface blocking peritoneal adhesion, which cannot reduce inflammation and suffers from limited anti-adhesion efficacy with unwanted side effects. Here, by exploiting the alternative activated macrophages to alleviate inflammation in adhesion development, a flexible graphene-composite-film (F-GCF) generating far-infrared (FIR) irradiation that effectively modulates the macrophage phenotype toward the anti-inflammatory M2 type, resulting in reduced PPA formation, is designed. The anti-adhesion effect of the FIR generated by F-GCF is determined in the rat abdominal wall abrasion-cecum defect models, which exhibit reduced incidence and area of PPA by 67.0% and 92.1% after FIR treatment without skin damage, significantly superior to the clinically used chitosan hydrogel. Notably, within peritoneal macrophages, FIR reduces inflammation reaction and promotes tissue plasminogen activator (t-PA) level via the polarization of peritoneal macrophages through upregulating Nr4a2 expression. To facilitate clinical use, a wirelessly controlled, wearable, F-GCF-based FIR therapy apparatus (GRAFT) is further developed and its remarkable anti-adhesion ability in the porcine PPA model is revealed. Collectively, the physical, biochemical, and in vivo preclinical data provide compelling evidence demonstrating the clinical-translational value of FIR in PPA prevention.

Changing patterns and surgical outcomes of small bowel obstruction in the era of minimally invasive surgery for colorectal cancer

INTRODUCTION

This study aimed to investigate whether the incidence, patterns, and surgical outcomes of small bowel obstruction (SBO) have changed in the era of minimally invasive surgery (MIS) for primary colorectal cancer (CRC).

METHODS

Consecutive patients who underwent laparotomy for SBO were divided into MIS and traditional open surgery (TOS) groups based on the previous colorectal cancer operation technique used. The MIS group was selected from 1544 consecutive patients who underwent MIS as a treatment for primary CRCs between 2014 and 2022, while the TOS group was selected from 1604 consecutive patients who underwent TOS as a treatment for primary CRCs between 2004 and 2013. The demographics, clinicopathological features, and surgical outcomes were compared between the two groups.

RESULTS

The SBO incidence in patients who underwent MIS for primary CRC was significantly lower than that in patients who underwent TOS (4.4%, n =68/1544 vs. 9.7%, n =156/1604, P <0.0001). Compared with the TOS group, the MIS group had significantly different ( P <0.0001) SBO patterns: adhesion (48.5 vs. 91.7%), internal herniation (23.5 vs. 2.6%), external herniation (11.8 vs. 1.9%), twisted bowel limbs (4.4 vs. 0.6%), ileal volvulus with pelvic floor adhesion (5.9 vs. 1.9%), and nonspecific external compression (5.9 vs. 1.3%). A subset analysis of patients with adhesive SBO (ASBO) showed that the MIS group tended to ( P <0.0001) have bands or simple adhesions (75.8%), whereas the TOS group predominantly had matted-type adhesions (59.4%). Furthermore, SBO in the MIS group had an acute (<3 months) or early (3-12 months) onset (64.7%), while that in the TOS group ( P <0.0001) had an intermediate or a late onset. When the surgical outcomes of SBO were evaluated, the TOS group had significantly more ( P <0.0001) blood loss and longer operation time; however, no significant difference was observed in the surgical morbidity/mortality (Clavien-Dindo classification ≧3, 11.8 vs. 14.1%, P =0.6367), hospitalization, and readmission rates between the two groups. Postoperative follow-up showed that the estimated 3-year (11.37 vs. 18.8%) and 6-year (25.54 vs. 67.4%) recurrence rates of SBO were significantly lower ( P =0.016) in the MIS group than in the TOS group.

CONCLUSIONS

The wide adoption of MIS to treat primary CRC has led to a lower incidence, altered patterns, and reduced recurrence rates of SBO. Awareness of this new trend will help develop surgical techniques to prevent incomplete restoration of anatomical defects and bowel malalignments specifically associated with MIS for CRC, as well as facilitate timely and appropriate management of SBO complications whenever they occur.

National Estimates of Short- and Longer-Term Hospital Readmissions After Major Surgery Among Community-Living Older Adults

Importance

Nationally representative estimates of hospital readmissions within 30 and 180 days after major surgery, including both fee-for-service and Medicare Advantage beneficiaries, are lacking.

Objectives

To provide population-based estimates of hospital readmission within 30 and 180 days after major surgery in community-living older US residents and examine whether these estimates differ according to key demographic, surgical, and geriatric characteristics.

Design, Setting, and Participants

A prospective longitudinal cohort study of National Health and Aging Trends Study data (calendar years 2011-2018), linked to records from the Centers for Medicare & Medicaid Services (CMS). Data analysis was conducted from April to August 2023. Participants included community-living US residents of the contiguous US aged 65 years or older who had at least 1 major surgery from 2011 to 2018. Data analysis was conducted from April 10 to August 28, 2023.

Main Outcomes and Measures

Major operations and hospital readmissions within 30 and 180 days were identified through data linkages with CMS files that included both fee-for-service and Medicare Advantage beneficiaries. Data on frailty and dementia were obtained from the annual National Health and Aging Trends Study assessments.

Results

A total of 1780 major operations (representing 9 556 171 survey-weighted operations nationally) were identified from 1477 community-living participants; mean (SD) age was 79.5 (7.0) years, with 56% being female. The weighted rates of hospital readmission were 11.6% (95% CI, 9.8%-13.6%) for 30 days and 27.6% (95% CI, 24.7%-30.7%) for 180 days. The highest readmission rates within 180 days were observed among participants aged 90 years or older (36.8%; 95% CI, 28.3%-46.3%), those undergoing vascular surgery (45.8%; 95% CI, 37.7%-54.1%), and persons with frailty (36.9%; 95% CI, 30.8%-43.5%) or probable dementia (39.0%; 95% CI, 30.7%-48.1%). In age- and sex-adjusted models with death as a competing risk, the hazard ratios for hospital readmission within 180 days were 2.29 (95% CI, 1.70-3.09) for frailty and 1.58 (95% CI, 1.15-2.18) for probable dementia.

Conclusions and Relevance

In this nationally representative cohort study of community-living older US residents, the likelihood of hospital readmissions within 180 days after major surgery was increased among older persons who were frail or had probable dementia, highlighting the potential value of these geriatric conditions in identifying those at increased risk.

Reduced Long-Term Bowel Obstruction Risk With Minimally Invasive Diaphragmatic Hernia Repair

INTRODUCTION

The introduction of minimally invasive surgery (MIS) for repair of congenital diaphragmatic hernias (CDH) has reduced postoperative length of stay, postoperative opioid consumption, and provided a more esthetic repair. In adult abdominal surgery, minimally invasive techniques have been associated with decreased long-term rates of small bowel obstruction (SBO), although it is unclear if this benefit carries over into the pediatric population. Our objective was to evaluate the rates of SBO following open versus MIS CDH repair.

MATERIAL AND METHODS

Infants who underwent CDH repair between 2010 and 2021 were identified using the PearlDiver Mariner database. Kaplan-Meier curves and Cox proportional hazards models were used to evaluate time to SBO by surgical approach (MIS versus open) while adjusting for mesh use, patient sex, and length of stay.

RESULTS

Of 1033 patients that underwent CDH repair, 258 (25.0%) underwent a minimally invasive approach. The overall rate of SBO was 7.5% (n = 77). Rate of SBO following MIS repair was lower than open repair at 1 y (0.8% versus 5.1%), 3 y, (2.3% versus 9.0%), and 5 y (4.4% versus 10.1%, P = 0.004). Following adjustment, the rate of SBO following MIS repair remained significantly lower than open repair (adjusted hazard ratio: 0.37, 95% confidence interval: 0.18, 0.79).

CONCLUSIONS

Following CDH repair, long-term rates of SBO are lower among patients treated with MIS approaches. Long-term risk of SBO should be considered when selecting surgical approach for CDH patients.

Natural Underwater Bioadhesive Offering Cohesion Modulation via Hydrogen Bond Disruptor: A Highly Injectable and in Vivo Stable Remedy for Gastric Ulcer Resolution

Injectable bioadhesives are attractive for managing gastric ulcers through minimally invasive procedures. However, the formidable challenge is to develop bioadhesives that exhibit high injectability, rapidly adhere to lesion tissues with fast gelation, provide reliable protection in the harsh gastric environment, and simultaneously ensure stringent standards of biocompatibility. Here, a natural bioadhesive with tunable cohesion is developed based on the facile and controllable gelation between silk fibroin and tannic acid. By incorporating a hydrogen bond disruptor (urea or guanidine hydrochloride), the inherent network within the bioadhesive is disturbed, inducing a transition to a fluidic state for smooth injection (injection force <5 N). Upon injection, the fluidic bioadhesive thoroughly wets tissues, while the rapid diffusion of the disruptor triggers instantaneous in situ gelation. This orchestrated process fosters the formed bioadhesive with durable wet tissue affinity and mechanical properties that harmonize with gastric tissues, thereby bestowing long-lasting protection for ulcer healing, as evidenced through in vitro and in vivo verification. Moreover, it can be conveniently stored (≥3 m) postdehydration. This work presents a promising strategy for designing highly injectable bioadhesives utilizing natural feedstocks, avoiding any safety risks associated with synthetic materials or nonphysiological gelation conditions, and offering the potential for minimally invasive application.

Biocompatible Nanocomposites for Postoperative Adhesion: A State-of-the-Art Review

To reduce and prevent postsurgical adhesions, a variety of scientific approaches have been suggested and applied. This includes the use of advanced therapies like tissue-engineered (TE) biomaterials and scaffolds. Currently, biocompatible antiadhesive constructs play a pivotal role in managing postoperative adhesions and several biopolymer-based products, namely hyaluronic acid (HA) and polyethylene glycol (PEG), are available on the market in different forms (e.g., sprays, hydrogels). TE polymeric constructs are usually associated with critical limitations like poor biocompatibility and mechanical properties. Hence, biocompatible nanocomposites have emerged as an advanced therapy for postoperative adhesion treatment, with hydrogels and electrospun nanofibers among the most utilized antiadhesive nanocomposites for in vitro and in vivo experiments. Recent studies have revealed that nanocomposites can be engineered to generate smart three-dimensional (3D) scaffolds that can respond to different stimuli, such as pH changes. Additionally, nanocomposites can act as multifunctional materials for the prevention of adhesions and bacterial infections, as well as tissue healing acceleration. Still, more research is needed to reveal the clinical potential of nanocomposite constructs and the possible success of nanocomposite-based products in the biomedical market.

Prior abdominal surgery as a potential risk factor for colonic diverticulosis or diverticulitis

BACKGROUND

Abnormal colonic pressure profiles have been associated with an increased risk of colonic diverticulosis. A surgical history is a known risk factor for abdominal adhesions and these may lead to increased intraluminal colonic pressure.

AIM

To assess whether previous abdominal surgery is associated with colonic diverticulosis or diverticulitis.

METHODS

We analyzed data from a study of patients undergoing colonoscopy for different indications from 2020 through 2021. Patients completed a structured questionnaire concerning previous abdominal surgeries, dietary and lifestyle exposures including smoking, alcohol use and co-morbidities.

RESULTS

Three hundred and fifty-nine patients were included in the study. The mean age was 67.6 and 46% were females. Diabetes mellitus, hypertension, ischemic heart disease, chronic obstructive pulmonary disease, chronic renal failure, and body mass index were similar in the diverticulosis and control groups. The overall prevalence of colonic diverticulosis was 25% (91/359) and 48% of the patients had previous abdominal surgery. As expected, the prevalence of diverticulosis increased with age. There was no difference in the rate of previous abdominal surgery between patients with or without diverticulosis (49% vs 47%, P = 0.78). In regards to specific surgeries, inguinal hernia repair was significantly associated with diverticulosis (52% vs 20%, P = 0.001), but not diverticulitis. In contrast, appendectomy was not associated with diverticulosis (6% vs 14%, P = 0.048).

CONCLUSION

These findings suggest that post-operative abdominal adhesions inducing high colonic intraluminal pressures do not appear to be the mechanism for diverticula formation. Rather, inguinal hernia and diverticulosis may share similar connective tissue pathologies with no causative relationship between them.

Efficacy of Naldemedine on Intestinal Hypomotility and Adhesions in Rodent Models of Postoperative Ileus

Postoperative ileus (POI) often decreases patients' QOL because of prolonged hospitalization and readmission. Alvimopan, a peripheral μ-opioid receptor antagonist, is currently the only therapeutic drug for POI. The aim of this study was to examine the efficacy of naldemedine (a peripheral μ-opioid receptor antagonist with a non-competitive pharmacological profile different from that of alvimopan) on postoperative intestinal hypomotility and adhesion in rodent models, and compare it with the effects of alvimopan. Oral administration of naldemedine (0.3 mg/kg) and alvimopan (3 mg/kg) significantly inhibited the decrease in intestinal motility induced by mechanical irritation in mice (p < 0.01, for both). Naldemedine (1 mg/kg) significantly shortened the adhesion length in chemical-induced postoperative adhesion model rats (p < 0.05). Alvimopan (3 mg/kg) also significantly reduced the adhesion ratio (p < 0.01). These findings suggest that naldemedine is effective for postoperative intestinal hypomotility and adhesions in rodents (i.e., as for alvimopan). Thus, naldemedine may be a useful option for the treatment of POI.

Cyclical endometrial repair and regeneration: Molecular mechanisms, diseases, and therapeutic interventions

The endometrium is a unique human tissue with an extraordinary ability to undergo a hormone-regulated cycle encompassing shedding, bleeding, scarless repair, and regeneration throughout the female reproductive cycle. The cyclical repair and regeneration of the endometrium manifest as changes in endometrial epithelialization, glandular regeneration, and vascularization. The mechanisms encompass inflammation, coagulation, and fibrinolytic system balance. However, specific conditions such as endometriosis or TCRA treatment can disrupt the process of cyclical endometrial repair and regeneration. There is uncertainty about traditional clinical treatments' efficacy and side effects, and finding new therapeutic interventions is essential. Researchers have made substantial progress in the perspective of regenerative medicine toward maintaining cyclical endometrial repair and regeneration in recent years. Such progress encompasses the integration of biomaterials, tissue-engineered scaffolds, stem cell therapies, and 3D printing. This review analyzes the mechanisms, diseases, and interventions associated with cyclical endometrial repair and regeneration. The review discusses the advantages and disadvantages of the regenerative interventions currently employed in clinical practice. Additionally, it highlights the significant advantages of regenerative medicine in this domain. Finally, we review stem cells and biologics among the available interventions in regenerative medicine, providing insights into future therapeutic strategies.

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.

Postoperative Peritoneal Granulomatous Inflammation After the Application of Potato Starch-Based Anti-Adhesive Agent in Laparoscopic Endometriosis Surgery

Background

Endometriosis is a chronic inflammatory oestrogen-dependent disease. It is characterised by elevated inflammatory markers in the peritoneal milieu with subsequent adhesiogenesis. Nowadays, excisional, and ablative surgeries are considered the main treatment of endometriosis, and adhesiolysis is being performed almost routinely during these procedures. Postoperative adhesion formation is a significant concern for many surgeons, especially as endometriosis patients are assumed to be predisposed to adhesiogenesis. In order to minimise adhesiogenesis after endometriosis surgery, the usage of different barrier methods have been discussed in the literature. Recent studies aim to investigate the effect of potato starch preparations on adhesion formation in endometriosis patients.

Objectives

We aim to describe the findings of a second-look laparoscopy on patients who received a starch-based anti-adhesive agent.

Materials and Methods

We present a retrospective case series that included the medical, surgical, and histopathologic data of three patients.

Main outcome measures

Intraperitoneal adhesion formation and peritoneal inflammation.

Results

All three patients had de-novo adhesions during the second-look laparoscopy. Pathological examination revealed noncaseating granulomatosis of the peritoneum in all patients.

Conclusion

The use of potato starch-based agents as a peritoneal adhesion prophylaxis in laparoscopic endometriosis surgery could lead to granulomatous peritoneal inflammation. Correct application by avoiding powder remnants through complete rinsing and transformation to gel seems to be an important factor to avoid this adverse effect.

What is new?

We aim to highlight that potato starch-based anti-adhesive agents similar to the one used in this study could be a cause of adhesiogenesis and peritoneal inflammation.

Chronic Glucocorticoid Use is a Potential Risk Factor for Delayed Pancreatic Fistula after Laparoscopic Distal Pancreatectomy: A Retrospective Analysis

Pancreatic fistula is a potentially morbid complication after distal pancreatectomy. Chronic glucocorticoid use is one of the risk factors for pancreatic fistula in pancreaticoduodenectomy, though it has not been reported in distal pancreatectomy. We explored whether chronic glucocorticoid use can be a risk factor for pancreatic fistula in distal pancreatectomy. We reviewed 408 consecutive patients who underwent elective distal pancreatectomy from 2011 to 2021. We evaluated two kinds of pancreatic fistula (postoperative pancreatic fistula and delayed pancreatic fistula). We defined delayed pancreatic fistula as a patient who was re-admitted for pancreatic fistula after the first discharge from the hospital. Preoperative characteristics and postoperative outcomes were analyzed. Two hundred sixty-seven patients underwent open distal pancreatectomy, while 141 patients had laparoscopic distal pancreatectomy. A comparison of patient with and without chronic glucocorticoid use showed that only patients with chronic glucocorticoid use developed delayed pancreatic fistula (0% vs. 16.7%; p < 0.001). In addition, delayed pancreatic fistula occurred in only laparoscopic distal pancreatectomy patients with chronic glucocorticoid use (0% vs. 25.0%; p < 0.001). Although sample size is small, it is reasonable to presume that chronic glucocorticoid use is a potential risk factor for delayed pancreatic fistula in laparoscopic distal pancreatectomy.

Multifunctional calcium polyphenol networks reverse the hostile microenvironment of trauma for preventing postoperative peritoneal adhesions

Abdominal adhesions, a commonly observed complication of abdominal surgery, have a high incidence and adversely affect patients' physical and mental health. The primary causes of abdominal adhesions are intraoperative trauma, acute inflammatory response, bleeding, and foreign body infection. Because most current treatment approaches for abdominal adhesions are limited, improved and novel postoperative anti-adhesion regimens are urgently needed. In this study, we developed calcium polyphenol network (CaPN) microspheres based on the self-assembly of the natural triphenolic compound gallic acid and Ca2+ in solution. The physicochemical properties of CaPNs, including their hemostatic, antibacterial, antioxidant, and anti-inflammatory activities, were investigated in vitro. Bleeding and cecal-abdominal wall adhesion models were established to observe the hemostatic activity of CaPNs and their preventive effect on postoperative abdominal wall adhesion in vivo. The results showed that CaPNs significantly reduced inflammation, oxidative stress, fibrosis, and abdominal adhesion formation and had good hemostatic and antibacterial properties. Our findings suggest a novel strategy for the prevention of postoperative adhesions.

Nomogram for predicting adhesive small bowel obstruction following emergency gastrointestinal surgery

BACKGROUND

Postoperative adhesions are frequent and significant complications that typically arise following abdominal surgery. Currently, the existing evidence for predicting the risk of adhesive small bowel obstruction (ASBO) after emergency gastrointestinal surgery (EGS) remains inadequate. A reliable perioperative model that quantifies the risk of ASBO after EGS serves as a practical tool for guiding individually tailored surveillance.

METHODS

A consecutive series of 1296 patients who underwent EGS for radiologically confirmed bowel/visceral inflammation or perforation between 2012 and 2022 at a tertiary academic medical center were included in this study to establish a best-fit nomogram. The nomogram was externally validated by assessing discrimination and calibration using an independent cohort from a separate medical center.

RESULTS

A total of 116 patients (8.9%) developed at least one episode of ASBO after EGS during a median follow-up duration of 26 months. The results of multivariable logistic analysis indicated that male sex (P = 0.043), preoperative albumin level (P = 0.002), history of pelvic radiotherapy (P = 0.038), laparotomy (P = 0.044), and intensive care unit stay ≥ 72 h (P = 0.047) were identified as independent risk factors for developing ASBO. By incorporating these predictors, the developed nomogram exhibited good accuracy in risk estimation, as evidenced by a guide-corrected C-index score of 0.852 (95% CI 0.667-0.920) in the external validation cohort. Decision curve analysis and clinical impact curve demonstrated a clinically effective predictive model.

CONCLUSION

By incorporating the nomogram as a supplemental tool in perioperative management, it becomes possible to accurately assess the individual's likelihood of developing ASBOs. This quantification enables surgeons to implement appropriate preventive measures, ultimately leading to improved outcomes.

Carbon monoxide (CO) derived from the CO-releasing molecule CORM-2 reduces peritoneal adhesion formation in a rat model

BACKGROUND

Although low-dose carbon monoxide (CO) administration has been shown to have an anti-fibrotic effect in various fibrotic diseases, its effects on peritoneal adhesion (PA), one of the postoperative complications, are not elucidated. In this study, the effect of CO-releasing tricarbonyldichlororuthenium (II) dimer (CORM-2) administration on the formation of PA and the underlying factors of its potential effect were investigated.

METHODS AND RESULTS

After the induction of PA, rats were divided into four groups with 8 rats in each group. The rats received either (i) dimethyl sulfoxide:saline solution (1:10) as a vehicle, (ii) 2.5 mg/kg CORM-2, (iii) 5 mg/kg CORM-2, or (iv) inactive (i) CORM (iCORM) intragastrically every day for a duration of 7 days. PA was not induced in rats (n = 8) designated as sham controls. Gross, histological, immunohistochemical and quantitative real-time polymerase chain reaction analyses were performed to evaluate the effectiveness of CORM-2 administration. Gross analysis showed that CORM-2 administration reduced PA formation compared to rats treated with vehicle. Histological and immunohistochemical examinations showed that increased collagen deposition, myofibroblast accumulation, microvessel density, and M1 macrophage count in the peritoneal fibrosis area of vehicle-treated rats decreased following CORM-2 treatments. PCR analyses showed that CORM-2 treatments decreased hypoxia-induced Hif1a, profibrotic Tgfb1, ECM components Col1a1 and Col3a1, collagen degradation suppressor Timp1, fibrinolysis inhibitor Serpine1, and pro-inflammatory Tnf mRNA expressions, while increasing the M2 macrophage marker Arg1 mRNA expression.

CONCLUSIONS

These results suggested that CORM-2 administration reduces PA formation by affecting adhesiogenic processes such as pro-inflammatory response, fibrinolytic system, angiogenesis and fibrogenesis.

Feasibility and safety of hybrid transvaginal natural orifice transluminal endoscopic surgery for colon cancer: Protocol for a multicenter, single-arm, phase II trial (vNOTESCA)

Introduction

It has been a decade since the first patient with colon cancer underwent colectomy by hybrid transvaginal natural orifice transluminal endoscopic surgery (hvNOTES). However, the efficacy and safety of this procedure is not well established.

Methods

This study is an open-label, multicenter, single-arm, phase 2 trial undertaken at six centers in China. Female patients aged over 18 years and below 80 years old with an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, with pathologically proven, resectable, cT1-3N0-2M0 disease who have previously untreated colon cancer are eligible for inclusion. The primary endpoint is a composite of major intraoperative and postoperative complications (greater than grade III, the Common Terminology Criteria for Adverse Events [CTCAE], version 5.0). Secondary endpoints include conversion to laparoscopic or open surgery, postoperative concentration of C-Reactive Protein and procalcitonine, complete pathological assessment of complete mesocolic excision specimens, postoperative pain, amount of narcotic pain medication administered, time to first flatus after surgery, number of harvested lymph nodes, R0 resection rate, length of hospital stay, sexual function assessment, quality of recovery, satisfaction with surgical scars, quality of life, postoperative recurrence patterns, relapse-free survival, and overall survival.

Ethics and dissemination

The study was approved by the Research Ethics Committee, Renmin Hospital of Wuhan University, China, number: WDRY2022-K053. All patients will receive written information of the trial and provide informed consent before enrollment. The results of this trial will be disseminated in academic conferences and peer-reviewed medical journals.Trial registration number NCT04048421.

Analysis of abdominal adhesion using the ileostomy model

Abdominal adhesion occurs commonly in clinical practice, causing unfavorable symptoms and readmission. The ileostomy operation is a common surgical procedure and we utilized this model to evaluate abdominal adhesion. Adhesion grade score was calculated in 35 patients (Cohort 1) and subjected to correlation and receiver operating characteristic analysis. Then 98 consecutive patients (Cohort 2) who underwent ileostomy and ileostomy closure were included into a retrospective study. Logistic regression analysis was performed, and the risk of small bowel obstruction was also assessed. The time of ileostomy closure correlated with adhesion grade score in Cohort 1, justifying its use as an indicator of abdominal adhesion. All patients in Cohort 2 were then divided into the high- and low-adhesion group. A multi-variable logistic regression analysis indicated that type of surgery and peritoneum suture during ileostomy were significant factors affecting the risk of abdominal adhesion. Abdominal adhesion had the trend to prolong the length of stay postoperatively without increasing the risk of bowel obstruction. Nine patients suffered bowel obstruction, and age older than 65 significantly increased the risk. We proposed the ileostomy procedure to be a model of abdominal adhesion, and the operative time of ileostomy closure could be used as an alternative of adhesion score. Type of surgery and peritoneum suture may be risk factors of abdominal adhesion. Older age increased the risk of small bowel obstruction after ileostomy surgery.

An anti-inflammatory chondroitin sulfate-poly(lactic-co-glycolic acid) composite electrospinning membrane for postoperative abdominal adhesion prevention

Postoperative abdominal adhesion is a very common and serious complication, resulting in pain, intestinal obstruction and heavy economic burden. Post-injury inflammation that could activate the coagulation cascade and deposition of fibrin is a major cause of adhesion. Many physical barrier membranes are used to prevent abdominal adhesion, but their efficiency is limited due to the lack of anti-inflammatory activity. Here, an electrospinning membrane composed of poly(lactic-co-glycolic acid) (PLGA) providing support and mechanical strength and chondroitin sulfate (CS) conferring anti-inflammation activity is fabricated for preventing abdominal adhesion after injury. The PLGA/CS membrane shows a highly dense fiber network structure with improved hydrophilicity and good cytocompatibility. Importantly, the PLGA/CS membrane with a mass ratio of CS at 20% provides superior anti-adhesion efficiency over a native PLGA membrane and commercial poly(D, L-lactide) (PDLLA) film in abdominal adhesion trauma rat models. The mechanism is that the PLGA/CS membrane could alleviate the local inflammatory response as indicated by the promoted percentage of anti-inflammatory M2-type macrophages and decreased expression of pro-inflammatory factors, such as IL-1β, TNF-α and IL-6, resulting in the suppression of the coagulation system and the activation of the fibrinolytic system. Furthermore, the deposition of fibrin at the abdominal wall was inhibited, and the damaged abdominal tissue was repaired with the treatment of the PLGA/CS membrane. Collectively, the PLGA/CS electrospinning membrane is a promising drug-/cytokine-free anti-inflammatory barrier for post-surgery abdominal adhesion prevention and a bioactive composite for tissue regeneration.

One-year outcomes following operative or non-operative management of adhesional small bowel obstruction

BACKGROUND

A trial of initial non-operative management is recommended in stable patients with adhesional small bowel obstruction. However, recent retrospective studies have suggested that early operative management may be of benefit in reducing subsequent recurrences. This study aimed to compare recurrence rates and survival in patients with adhesional small bowel obstruction treated operatively or non-operatively.

METHODS

This was a prospective cohort study conducted at six acute hospitals in Denmark, including consecutive patients admitted with adhesional small bowel obstruction over a 4-month interval. Patients were stratified into two groups according to their treatment (operative versus non-operative) and followed up for 1 year after their index admission. Primary outcomes were recurrence of small bowel obstruction and overall survival within 1 year of index admission.

RESULTS

A total of 201 patients were included, 118 (58.7 per cent) of whom were treated operatively during their index admission. Patients undergoing operative treatment had significantly better 1-year recurrence-free survival compared with patients managed non-operatively (operative 92.5 per cent versus non-operative 66.6 per cent, P <0.001). However, when the length of index admission was taken into account, patients treated non-operatively spent significantly less time admitted to hospital in the first year (median 3 days non-operative versus 6 days operative, P <0.001). On multivariable analysis, operative treatment was associated with decreased risks of recurrence (HR 0.22 (95 per cent c.i. 0.10-0.48), P <0.001) but an increased all-cause mortality rate (HR 2.48 (95 per cent c.i. 1.13-5.46), P = 0.024).

CONCLUSION

Operative treatment of adhesional small bowel obstruction is associated with reduced risks of recurrence but increased risk of death in the first year after admission.

REGISTRATION NUMBER

NCT04750811 (http://www.clinicaltrials.gov).prior (registration date: 11 February 2021).

Pro-angiogenic photo-crosslinked silk fibroin hydrogel: a potential candidate for repairing alveolar bone defects

OBJECTIVE

This study aimed to develop a pro-angiogenic hydrogel with in situ gelation ability for alveolar bone defects repair.

METHODOLOGY

Silk fibroin was chemically modified by Glycidyl Methacrylate (GMA), which was evaluated by proton nuclear magnetic resonance (1H-NMR). Then, the photo-crosslinking ability of the modified silk fibroin was assessed. Scratch and transwell-based migration assays were conducted to investigate the effect of the photo-crosslinked silk fibroin hydrogel on the migration of human umbilical vein endothelial cells (HUVECs). In vitro angiogenesis was conducted to examine whether the photo-crosslinked silk fibroin hydrogel would affect the tube formation ability of HUVECs. Finally, subcutaneous implantation experiments were conducted to further examine the pro-angiogenic ability of the photo-crosslinked silk fibroin hydrogel, in which the CD31 and α-smooth muscle actin (α-SMA) were stained to assess neovascularization. The tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were also stained to evaluate inflammatory responses after implantation.

RESULTS

GMA successfully modified the silk fibroin, which we verified by our 1H-NMR and in vitro photo-crosslinking experiment. Scratch and transwell-based migration assays proved that the photo-crosslinked silk fibroin hydrogel promoted HUVEC migration. The hydrogel also enhanced the tube formation of HUVECs in similar rates to Matrigel®. After subcutaneous implantation in rats for one week, the hydrogel enhanced neovascularization without triggering inflammatory responses.

CONCLUSION

This study found that photo-crosslinked silk fibroin hydrogel showed pro-angiogenic and inflammation inhibitory abilities. Its photo-crosslinking ability makes it suitable for matching irregular alveolar bone defects. Thus, the photo-crosslinkable silk fibroin-derived hydrogel is a potential candidate for constructing scaffolds for alveolar bone regeneration.

Previous Abdominal Scars among Patients Undergoing Laparoscopic Cholecystectomy in a Tertiary Care Centre

Introduction

Abdominal scars result from various open abdominal surgeries. Laparoscopic surgery in previous open abdominal surgery possesses various challenges to the surgeon like gaining access to the abdominal cavity, and difficulty in dissection due to dense adhesions from previous surgeries for various intraabdominal pathologies. This study aimed to find out the prevalence of previous abdominal scars among patients undergoing laparoscopic cholecystectomy in a tertiary care centre.

Methods

A descriptive cross-sectional study was conducted among patients undergoing laparoscopic cholecystectomy in a tertiary care centre from 1 May 2022 to 30 April 2023 after taking ethical approval from the Institutional Review Committee. Palmer's point approach via Hassen open technique or direct optical entry was used for cases with previous abdominal scars to gain access to the abdominal cavity. Patients with symptomatic gallstone diseases were included in the study whereas patients with cholecystitis, pancreatitis, and previous cesarean scar were excluded. Convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval.

Results

Among 160 patients undergoing laparoscopic cholecystectomy, previous abdominal scars was found in 40 (25%) patients.

Conclusions

The prevalence of previous abdominal scars contributing to intraoperative and post-operative difficulties among patients undergoing laparoscopic cholecystectomy was found to be higher than in studies done in similar settings.

Keywords

laparoscopic cholecystectomy; open surgery; prevalence.

Prevention strategies of postoperative adhesion in soft tissues by applying biomaterials: Based on the mechanisms of occurrence and development of adhesions

Postoperative adhesion (POA) widely occurs in soft tissues and usually leads to chronic pain, dysfunction of adjacent organs and some acute complications, seriously reducing patients' quality of life and even being life-threatening. Except for adhesiolysis, there are few effective methods to release existing adhesion. However, it requires a second operation and inpatient care and usually triggers recurrent adhesion in a great incidence. Hence, preventing POA formation has been regarded as the most effective clinical strategy. Biomaterials have attracted great attention in preventing POA because they can act as both barriers and drug carriers. Nevertheless, even though much reported research has been demonstrated their efficacy on POA inhibition to a certain extent, thoroughly preventing POA formation is still challenging. Meanwhile, most biomaterials for POA prevention were designed based on limited experiences, not a solid theoretical basis, showing blindness. Hence, we aimed to provide guidance for designing anti-adhesion materials applied in different soft tissues based on the mechanisms of POA occurrence and development. We first classified the postoperative adhesions into four categories according to the different components of diverse adhesion tissues, and named them as "membranous adhesion", "vascular adhesion", "adhesive adhesion" and "scarred adhesion", respectively. Then, the process of the occurrence and development of POA were analyzed, and the main influencing factors in different stages were clarified. Further, we proposed seven strategies for POA prevention by using biomaterials according to these influencing factors. Meanwhile, the relevant practices were summarized according to the corresponding strategies and the future perspectives were analyzed.

Variation in the management of adhesive small bowel obstruction in the Netherlands: a prospective cross-sectional study

BACKGROUND

ASBO is a frequent abdominal surgical emergency and a leading cause of morbidity and mortality in emergency surgery. The aim of this study is to provide insight into the current management of adhesive small bowel obstruction (ASBO) and associated outcomes.

METHODS AND MATERIALS

A nationwide prospective cross-sectional cohort study was conducted. All patients with clinical signs of ASBO admitted to participating Dutch hospitals were included during a 6 months inclusion period between April 2019 and December 2020. Ninety-day clinical outcomes were described and compared for nonoperative management (NOM) and laparoscopic and open surgery.

RESULTS

In 34 participating hospitals, 510 patients were included, of whom 382 (74.9%) had a definitive diagnosis of ASBO. Initial management consisted of emergency surgery in 71 (18.6%) patients and NOM in 311 (81.4%) patients, 119 (31.1%) of whom required delayed surgery after failure of NOM. Surgical interventions started laparoscopically in 51.1%, of which 36.1% were converted to laparotomy. Intentional laparoscopy resulted in shorter hospital stays compared with open surgery (median 8.0 vs. 11.0 days; P <0.001) and comparable hospital mortality (5.2 vs. 4.3%; P =1.000). Oral water-soluble contrast use was associated with a decreased length of stay ( P =0.0001). Hospital stay for surgical patients was shorter in patients who were operated on within 72 h of admission ( P <0.001).

CONCLUSION

This nationwide cross-sectional study demonstrates shorter hospital stay in ASBO patients who received water-soluble contrast, were operated within 72 h of admission or were operated with minimally invasive techniques. Results may support the standardization of ASBO treatment.

Predicting long-term risk of reoperations following abdominal and pelvic surgery: a nationwide retrospective cohort study

BACKGROUND

The risk of reoperations after abdominal and pelvic surgery is multifactorial and difficult to predict. The risk of reoperation is frequently underestimated by surgeons as most reoperations are not related to the initial procedure and diagnosis. During reoperation, adhesiolysis is often required, and patients have an increased risk of complications. Therefore, the aim of this study was to provide an evidence-based prediction model based on the risk of reoperation.

MATERIALS AND METHODS

A nationwide cohort study was conducted including all patients undergoing an initial abdominal or pelvic operation between 1 June 2009 and 30 June 2011 in Scotland. Nomograms based on multivariable prediction models were constructed for the 2-year and 5-year overall risk of reoperation and risk of reoperation in the same surgical area. Internal cross-validation was applied to evaluate reliability.

RESULTS

Of the 72 270 patients with an initial abdominal or pelvic surgery, 10 467 (14.5%) underwent reoperation within 5 years postoperatively. Mesh placement, colorectal surgery, diagnosis of inflammatory bowel disease, previous radiotherapy, younger age, open surgical approach, malignancy, and female sex increased the risk of reoperation in all the prediction models. Intra-abdominal infection was also a risk factor for the risk of reoperation overall. The accuracy of the prediction model of risk of reoperation overall and risk for the same area was good for both parameters ( c -statistic=0.72 and 0.72).

CONCLUSIONS

Risk factors for abdominal reoperation were identified and prediction models displayed as nomograms were constructed to predict the risk of reoperation in the individual patient. The prediction models were robust in internal cross-validation.

Financial and Inpatient Burden of Adhesion-Related Small Bowel Obstruction: A Systematic Review of the Literature

BACKGROUND

Postoperative adhesions may occur after >90% of laparotomies and is the most common cause of small bowel obstruction (SBO). Despite the high incidence, there is a lack of data related to financial implications of adhesion-related SBO (ASBO). This systematic literature review of in-hospital costs for treatment of ASBO searched PubMed, Scopus and Google Scholar databases according to PRISMA guidelines. Exclusion criteria were reviews, editorials, clinical vignettes, studies of patients <18 years of age, studies with no English full text and studies assessing adhesiolysis for causes other than SBO or that used extrapolations with economic models. Main outcome measures were financial costs per patient and national costs.

RESULTS

Seven studies, published between 1999 and 2016, incorporating a total of 39 573 patients, were identified. Four were undertaken in European countries, one in the USA, 1 in New Zealand and 1 in Nigeria. Overall national costs regarding treatment of patients with ASBO ranged between $3.468 million and $1.77 billion. Median overall cost in the medical management group was $2371.5 ($1814-$2568) vs $12370 ($4914-$25321) in the surgical group. Median length of stay was 4 (3-7) days for patients conservatively treated and 11.5 (8-16.3) days for patients who underwent surgery. Median length of stay of operated patients on was almost triple that of patients conservatively managed.

CONCLUSIONS

Given the major financial implications of ASBO, further initiatives are needed to avoid operations for SBO when clinically appropriate and minimize delays taking patients with high suspicion of complete SBO to the operating room.

Hotspots and difficulties of biliary surgery in older patients

ABSTRACT

With the accelerated aging society in China, the incidence of biliary surgical diseases in the elderly has increased significantly. The clinical characteristics of these patients indicate that improving treatment outcomes and realizing healthy aging are worthy of attention. How to effectively improve the treatment effect of geriatric biliary surgical diseases has attracted widespread attention. This paper reviews and comments on the hotspots and difficulties of biliary surgery in older patients from six aspects: (1) higher morbidity associated with an aging society, (2) prevention and control of pre-operative risks, (3) extending the indications of laparoscopic surgery, (4) urgent standardization of minimally invasive surgery, (5) precise technological progress in hepatobiliary surgery, and (6) guarantee of peri-operative safety. It is of great significance to fully understand the focus of controversy, actively make use of its favorable factors, and effectively avoid its unfavorable factors, for further improving the therapeutic effects of geriatric biliary surgical diseases, and thus benefits the vast older patients with biliary surgical diseases. Accordingly, a historical record with the highest age of 93 years for laparoscopic transcystic common bile duct exploration has been created by us recently.

A feasible and safe approach for repeat laparoscopic liver resection and patient selection based on standardized preoperative prediction of surgical difficulty

PURPOSE

This study was performed to propose a strategy for repeat laparoscopic liver resection (RLLR) and investigate the preoperative predictive factors for RLLR difficulty.

METHODS

Data from 43 patients who underwent RLLR using various techniques at 2 participating hospitals from April 2020 to March 2022 were retrospectively reviewed. Surgical outcomes, short-term outcomes, and feasibility and safety of the proposed techniques were evaluated. The relationship between potential predictive factors for difficult RLLR and perioperative outcomes was evaluated. Difficulties associated with RLLR were analyzed separately in two surgical phases: the Pringle maneuver phase and the liver parenchymal transection phase.

RESULTS

The open conversion rate was 7%. The median surgical time and intraoperative blood loss were 235 min and 200 mL, respectively. The Pringle maneuver was successfully performed in 81% of patients using the laparoscopic Satinsky vascular clamp (LSVC). Clavien-Dindo class ≥III postoperative complications were observed in 12% of patients without mortality. An analysis of the risk factors for predicting difficult RLLR showed that a history of open liver resection was an independent risk factor for difficulty in the Pringle maneuver phase.

CONCLUSION

We present a feasible and safe approach to address RLLR difficulty, especially difficulty with the Pringle maneuver using an LSVC, which is extremely useful in RLLR. The Pringle maneuver is more challenging in patients with a history of open liver resection.

Biocompatible and biodegradable chitin-based hydrogels crosslinked by BDDE with excellent mechanical properties for effective prevention of postoperative peritoneal adhesion

Postoperative peritoneal adhesions are common complications caused by abdominal and pelvic surgery, which seriously impact the quality of life of patients and impose additional financial burdens. Using of biomedical materials as physical barriers to completely isolate the traumatic organ and injured tissue is an optimal strategy for preventing postoperative adhesions. However, the limited efficacy and difficulties in the complete degradation or integration of biomedical materials with living tissues restrict the application of these materials. In this study, novel chitin-based crosslinked hydrogels with appropriate mechanical properties and flexibilities were developed using a facile and green strategy. The developed hydrogels simultaneously exhibited excellent biocompatibilities and resistance to nonspecific protein adsorption and NIH/3T3 fibroblast adhesion. Furthermore, these hydrogels were biodegradable and could be completely integrated into the native extracellular matrix. The chitin-based crosslinked hydrogels also effectively inhibited postoperative peritoneal adhesions in rat models of adhesion and recurrence. Therefore, these novel chitin-based crosslinked hydrogels are excellent candidate physical barriers for the efficient prevention of postoperative peritoneal adhesions and provide a new anti-adhesion strategy for biomedical applications.

Recurrence After Operated Adhesive Small Bowel Obstruction: Development and Validation of a Predictive Model

OBJECTIVE

Recurrence after operated adhesive small bowel obstruction (ASBO) is a threatening potentiality for patients and a therapeutic dilemma facing any surgeon. Yet, little is known about screening tools to identify patients at higher risk of recurrence. The present study aimed to determine the risk factors of recurrence in patients operated on for ASBO and to construct a reliable predictive model capable of quantifying the risk of recurrence, which will be a practical tool to guide individualized patient management.

METHODS

We developed a best-fit nomogram using data from a training cohort of 454 patients with ASBO treated surgically at the Affiliated Hospital of Qingdao University from 2012 through 2021. The nomogram was developed based on variables independently associated with recurrent ASBO screened via multivariate logistic regression. This model was validated using data from an independent internal cohort of 194 patients at the same institution and an external cohort of 196 patients at Qilu Hospital of Shandong University. Both internal and external validation was performed with a bootstrap resampling method (1000 iterations). The predictive accuracy of the nomogram was evaluated using Harrell's concordance index (C index) and calibration curve.

RESULTS

Eight-one out of 648 (12.5%) patients experienced at least one ASBO relapse with a median follow-up of 37 (interquartile range, 18-70) months. Univariate and multivariate analyses identified the following independent predictive factors associated with recurrence: diabetes mellitus (P = 0.004), preoperative albumin levels (P = 0.002), omentectomy (P = 0.002), matted adhesions (P = 0.036), and the approach of surgery (P = 0.008). Incorporating these five predictors, our nomogram predicted recurrent ASBO with C-index scores of 0.932 (95% CI 0.867-0.996) in the training cohort, 0.874 (95% CI 0.706-1) in the internal validation cohort, and 0.852 (95% CI 0.667-0.920) in the external validation cohort. The predictive model showed a very good fitting degree.

CONCLUSIONS

The development of a practical, easy-to-use nomogram for calculating the risk of recurrence in patients with ASBO treated surgically will enable physicians to tailor therapeutic strategies and monitor disease in advance.

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.

Herbal formula Jiawei Xiaochengqi decoction prevents postoperative abdominal adhesion in a rat model through inhibition of CXCL2-CXCR2 pathway

BACKGROUND

Postoperative abdominal adhesion (PAA) is the most common complication after abdominal surgeries, which can lead to intestinal obstruction, chronic abdominal pain or female infertility. Jiawei Xiaochengqi decoction (JWXCQ) is a hospital preparation widely used for PAA treatment in Nanfang Hospital of Southern Medical University for more than twenty years.

PURPOSE

This study aimed to investigate the therapeutic effects and potential mechanism of JWXCQ against PAA and provide beneficial information for its clinical application.

METHODS

The main active components of JWXCQ were identified using ultra high performance liquid chromatography (UHPLC) combined with standard substance comparison. The efficacy and underlying mechanism of JWXCQ were evaluated through in vivo experiments with a postsurgical-induced peritoneal adhesion rat model, and in vitro studies with LPS-stimulated Raw 264.7 macrophages and primary fibroblasts. H&E and Masson staining were performed to assess histopathological changes. The levels of cytokines/proteins-associated with inflammation and degradation of extracellular matrix as well as CXCL2-CXCR2 pathway-related proteins were determined by ELISA, qRT-PCR, western blot assays or immunohistochemistry, respectively. Furthermore, siCXCR2 transfection was used to validate the mechanism of action of JWXCQ.

RESULTS

JWXCQ treatment significantly reduced the formation of PAA, inhibited the inflammation and collagen deposition, and facilitated the secretion of MMP9, decreased the levels of IL-1β, IL-6, TIMP1, COL-1, and suppressed the CXCL2-CXCR2 pathway in PAA rats. Furthermore, JWXCQ inhibited its downstream pathways, the JAK2-STAT3 and PI3K-AKT signaling, as indicated by the suppression of the phosphorylation levels of STAT3 and AKT. In vitro cell experiments revealed that JWXCQ reduced IL-1β and IL-6 secretion in Raw 264.7 macrophages and COL-1 in primary fibroblasts. The CXCL2-CXCR2, JAK2-STAT3 and PI3K-AKT pathways were also inhibited after JWXCQ treatment, which were consistent with the in vivo results. More importantly, silence of CXCR2 eliminated the regulatory effects of JWXCQ.

CONCLUSION

JWXCQ could effectively prevent the PAA formation by alleviating inflammation and collagen deposition, which was associated with the inhibition of CXCL2-CXCR2 pathway. This study investigated the relevant pharmacological mechanisms of JWXCQ, providing further evidence for the application of JWXCQ in clinical PAA treatment.

Multifunctional Microgel-Based Cream Hydrogels for Postoperative Abdominal Adhesion Prevention

Postoperative abdominal adhesions are a common problem after surgery and can produce serious complications. Current antiadhesive strategies focus mostly on physical barriers and are unsatisfactory and inefficient. In this study, we designed and synthesized advanced injectable cream-like hydrogels with multiple functionalities, including rapid gelation, self-healing, antioxidation, anti-inflammation, and anti-cell adhesion. The multifunctional hydrogels were facilely formed by the conjugation reaction of epigallocatechin-3-gallate (EGCG) and hyaluronic acid (HA)-based microgels and poly(vinyl alcohol) (PVA) based on the dynamic boronic ester bond. The physicochemical properties of the hydrogels including antioxidative and anti-inflammatory activities were systematically characterized. A mouse cecum-abdominal wall adhesion model was implemented to investigate the efficacy of our microgel-based hydrogels in preventing postoperative abdominal adhesions. The hydrogels, with a high molecular weight HA, significantly decreased the inflammation, oxidative stress, and fibrosis and reduced the abdominal adhesion formation, compared to the commercial Seprafilm group or Injury-only group. Label-free quantitative proteomics analysis demonstrated that S100A8 and S100A9 expressions were associated with adhesion formation; the microgel-containing hydrogels inhibited these expressions. The microgel-containing hydrogels with multifunctionality decreased the formation of postoperative intra-abdominal adhesions in a murine model, demonstrating promise for clinical applications.

Oral Administration Evaluation of the Hydro-Ethanolic Extract of Ginger (Rhizome of Zingiber officinale) against Postoperative-Induced Peritoneal Adhesion: Investigating the Role of Anti-Inflammatory and Antioxidative Effects

Peritoneal adhesions (PAs) occur and develop after abdominal surgery. Abdominal adhesions are common and often develop after abdominal surgery. Currently, there are no effective targeted pharmacotherapies for treating adhesive disease. In this regard, ginger is wildly used in traditional medicine because of its anti-inflammatory and antioxidant effects and has been investigated for peritoneal adhesion treatment. This study analyzed ginger ethanolic extraction via HPLC to have a 6-gingerol concentration. Four groups induced peritoneal adhesion to evaluate ginger's effects on peritoneal adhesion. Then, ginger extract (50, 150, and 450 mg/kg) was administered by gavage in various groups of male Wistar rats (220 ± 20 g, 6-8 weeks). After scarifying the animals for biological assessment, macroscopic and microscopic parameters were determined via scoring systems and immunoassays in the peritoneal lavage fluid. Next, the adhesion scores and interleukin IL-6, IL-10, tumor necrosis factor-(TNF-) α, transforming growth factor-(TGF-) β1, vascular endothelial growth factor (VEGF), and malondialdehyde (MDA) were elevated in the control group. The results showed that ginger extract (450 mg/kg) notably decreased inflammatory (IL-6 and TNF-α), fibrosis (TGF-β1), anti-inflammatory cytokine (IL-10), angiogenesis (VEGF), and oxidative (MDA) factors, while increased antioxidant factor glutathione (GSH), compared to the control group. These findings suggest that a hydro-alcoholic extract of ginger is a potentially novel therapeutic strategy for inhibiting adhesion formation. Also, it might be considered a beneficial anti-inflammatory or antifibrosis herbal medicine in clinical trials. However, further clinical studies are required to approve the effectiveness of ginger.

Risk Factors for Adhesion-Related Readmission and Abdominal Reoperation after Gynecological Surgery: A Nationwide Cohort Study

More than half of women in developed countries undergo surgery during their lifetime, putting them at risk of adhesion-related complications. Adhesion-related complications include small bowel obstruction, chronic (pelvic) pain, subfertility, and complications associated with adhesiolysis during reoperation. The aim of this study is to predict the risk for adhesion-related readmission and reoperation after gynecological surgery. A Scottish nationwide retrospective cohort study was conducted including all women undergoing a gynecological procedure as their initial abdominal or pelvic operation between 1 June 2009 and 30 June 2011, with a five-year follow-up. Prediction models for two- and five-year risk of adhesion-related readmission and reoperation were constructed and visualized using nomograms. To evaluate the reliability of the created prediction model, internal cross-validation was performed using bootstrap methods. During the study period, 18,452 women were operated on, and 2719 (14.7%) of them were readmitted for reasons possibly related to adhesions. A total of 2679 (14.5%) women underwent reoperation. Risk factors for adhesion-related readmission were younger age, malignancy as indication, intra-abdominal infection, previous radiotherapy, application of a mesh, and concomitant inflammatory bowel disease. Transvaginal surgery was associated with a lower risk of adhesion-related complications as compared to laparoscopic or open surgeries. The prediction model for both readmissions and reoperations had moderate predictive reliability (c-statistics 0.711 and 0.651). This study identified risk factors for adhesion-related morbidity. The constructed prediction models can guide the targeted use of adhesion prevention methods and preoperative patient information in decision-making.

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.

Lumbrokinase, a Fibrinolytic Enzyme, Prevents Intra-Abdominal Adhesion by Inhibiting the Migrative and Adhesive Activities of Fibroblast via Attenuation of the AP-1/ICAM-1 Signaling Pathway

Intra-abdominal adhesion is a complication following abdominal surgery caused by the suppression of fibrinolytic activity and aggravated fibroblast invasion of the injured area, which may lead to chronic illnesses such as chronic pain, intestinal obstruction, and female infertility. This study hypothesized that lumbrokinase, a fibrinolytic enzyme extracted from the earthworm, supports the wound healing process. Therefore, we assessed the effect of lumbrokinase on intra-abdominal adhesion. Lumbrokinase treatment significantly decreased the severity and the area of intra-abdominal adhesion in vivo in a dose-dependent manner compared with the controls (untreated and hyaluronate-treated). Lumbrokinase-associated adverse effects were not observed. Immunohistochemical analysis of adhesion tissues revealed a loosened adhesive band between tissues, coupled with significantly decreased peritoneal thickening in the lumbrokinase-treated group versus the control group. Three-dimensional spheroid, MTT, and scratch wound migration assays using the IMR-90 human fibroblast cell line demonstrated that lumbrokinase significantly attenuated the migration and adhesive activity of fibroblasts without compromising cell proliferation. The luciferase assay and western blot analysis showed that lumbrokinase inhibited the AP-1/ICAM-1 cell adhesion signaling pathway. Therefore, lumbrokinase decreases intra-abdominal adhesion and peritoneal thickening by augmenting fibrinolytic action and inhibiting fibroblast migration and adhesive activity via attenuation of the AP-1/ICAM-1 signaling pathway. Lumbrokinase is thus a promising agent to prevent intra-abdominal adhesion.

Lipid emulsions prevent postoperative abdominal adhesions

INTRODUCTION

Adhesions are the most common cause of long-term morbidity after abdominal surgery and most often cause various forms of intestinal passage disorders ranging from partial obstruction to complete, life-threatening intestinal obstruction. The aim of the present study was to evaluate the protective effect of intraperitoneally administered lipid emulsions on the formation of adhesions in larger animal model, as the lubricating effect of phospholipids and the mechanical barrier of the lipid component are combined with the anti-inflammatory effect of fish oil.

METHODS

Thirty-one female domestic pigs were randomly divided into three groups. At the end of the surgical procedure, a lipid emulsion or saline solution was applied intraperitoneally. After 14 days, an independent macroscopic, histological and immunohistochemical evaluation of the adhesions were performed.

RESULTS

Intraperitoneal administration of lipid emulsions significantly reduced the incidence of intra-abdominal adhesions. Microscopic examination demonstrated a significant reduction in the number of inflammatory elements and the amount of collagen in the adhesions, especially after administration of the fish oil-based emulsion. A simultaneous decrease in neovascularization was observed in the adhesions. Evaluation of the intestinal anastomosis did not reveal significant differences in healing between the groups.

CONCLUSION

Intraperitoneal administration of lipid emulsions can reduce the development of postoperative intra-abdominal adhesions by the combined action of phospholipids as important lubricants and lipids as a mechanical barrier. Their effect is caused by a reduction in proinflammatory and profibrotic mediators. At the same time, intraperitoneal administration of lipid emulsions does not impair healing of the anastomosis in larger animal model.

Progress in diagnosis and treatment of surgery-related adhesive small intestinal obstruction

Adhesive small bowel obstruction is a relatively common surgical acute abdomen, which is caused by various factors that result in the contents of the small bowel failing to pass smoothly. The clinical symptoms include abdominal pain, distension, nausea and vomiting, and defecation disorder. The chance of adhesive small bowel obstruction to develop in patients with a history of abdominal surgery is around 2.4%. This paper discusses the most recent developments in the conservative and surgical management of adhesive small bowel obstruction based on clinical manifestation, laboratory analysis, and imaging examination.

Validation of appendiceal stump invagination in laparoscopic appendectomy

INTRODUCTION

There are various methods for appendiceal stump dissection, but the necessity for stump invagination remains unclear. This study aimed to assess the efficacy of appendiceal stump invagination in patients with acute appendicitis after laparoscopic appendectomy (LA).

METHODS

We enrolled 327 patients with acute appendicitis who underwent LA between 2012 and 2020. Perioperative variables and surgical outcomes were analyzed between the invagination of the appendiceal stump and noninvagination groups. Propensity score-matched analysis (PSM) was performed.

RESULTS

More patients experienced severe inflammation and severe intra-abdominal contamination in the noninvagination group than in the invagination group. Patients in the noninvagination group had an older age, higher body mass index, and poorer American Society of Anesthesiologists physical status than the invagination group. Severe inflammation in the noninvagination group was associated with longer hospital stays and poorer postoperative complications than in the invagination group. PSM analysis was performed to minimize bias in the two groups. After PSM analysis, there were no significant differences in surgical site infection, postoperative intra-abdominal abscess, Clavien-Dindo class ≥IIIa, or postoperative stay between the two groups. During the follow-up period, the postoperative adhesive ileus was not significantly different between the invagination and noninvagination groups.

CONCLUSION

Invagination of the appendiceal stump during LA is not necessary to prevent short- and long-term complications. Even in cases dissected using a laparoscopic endostapler, the appendiceal stump per se is not related to postoperative adhesive ileus.

Adhesions in abdomino-pelvic surgeries: A real economic impact?

STUDY OBJECTIVE

To evaluate the epidemiologic and economic burden related to adhesions and their complications for the French healthcare system.

DESIGN

A descriptive and economic retrospective analysis.

SETTING

Medicalized information system program (PMSI), national scale of costs.

PATIENTS

Female patients operated on to treat adhesions related complications in 2019.

INTERVENTIONS

All patients with coded adhesiolysis acts were selected in order to identify the characteristics of Diagnosis related groups (DRG) and compare them with the general DRGs. Then, a sub-analysis on surgery types (laparoscopy or open procedures) was performed to evaluate impact adhesions development and Length of Stay. Lastly, direct costs of adhesions for the healthcare system were quantified based upon adhesiolysis acts coded as main diagnosis.

MEASUREMENTS AND MAIN RESULTS

26.387 adhesiolysis procedures were listed in France in 2019 through 8 adhesiolysis acts regrouping open surgeries and laparoscopic procedures. Adhesiolysis was coded in up to 34% in some DRGs for laparoscopic procedures. 1551 (1461 studied in our study) surgeries have been realized in 2019 with main procedure: adhesiolysis. These surgeries were associated with an expense of €4 million for the healthcare system for rehospitalizations and reoperations only. Social costs such as sick leaves, drugs and other cares haven't been taken in consideration.

CONCLUSION

Adhesions related complications represent a massive burden for patients and an expensive problem for society. These difficulties may likely to be reduced by a broader use of antiadhesion barriers, at least in some targeted procedures.

Mechanisms of Peritoneal Mesothelial Cells in Peritoneal Adhesion

A peritoneal adhesion (PA) is a fibrotic tissue connecting the abdominal or visceral organs to the peritoneum. The formation of PAs can induce a variety of clinical diseases. However, there is currently no effective strategy for the prevention and treatment of PAs. Damage to peritoneal mesothelial cells (PMCs) is believed to cause PAs by promoting inflammation, fibrin deposition, and fibrosis formation. In the early stages of PA formation, PMCs undergo mesothelial–mesenchymal transition and have the ability to produce an extracellular matrix. The PMCs may transdifferentiate into myofibroblasts and accelerate the formation of PAs. Therefore, the aim of this review was to understand the mechanism of action of PMCs in PAs, and to offer a theoretical foundation for the treatment and prevention of PAs.

Bottlebrush inspired injectable hydrogel for rapid prevention of postoperative and recurrent adhesion

Postsurgical adhesion is a common clinic disease induced by surgical trauma, accompanying serious subsequent complications. Current non-surgical approaches of drugs treatment and biomaterial barrier administration only show limited prevention effects and couldn't effectively promote peritoneum repair. Herein, inspired by bottlebrush, a novel self-fused, antifouling, and injectable hydrogel is fabricated by the free-radical polymerization in aqueous solution between the methacrylate hyaluronic acid (HA-GMA) and N-(2-hydroxypropyl) methacrylamide (HPMA) monomer without any chemical crosslinkers, termed as H-HPMA hydrogel. The H-HPMA hydrogel can be tuned to perform excellent self-fused properties and suitable abdominal metabolism time. Intriguingly, the introduction of the ultra-hydrophilic HPMA chains to the H-HPMA hydrogel affords an unprecedented antifouling capability. The HPMA chains establish a dense hydrated layer that rapidly prevents the postsurgical adhesions and recurrent adhesions after adhesiolysis in vivo. The H-HPMA hydrogel can repair the peritoneal wound of the rat model within 5 days. Furthermore, an underlying mechanism study reveals that the H-HPMA hydrogel significantly regulated the mesothelial-to-mesenchymal transition (MMT) process dominated by the TGF-β-Smad2/3 signal pathway. Thus, we developed a simple, effective, and available approach to rapidly promote peritoneum regeneration and prevent peritoneal adhesion and adhesion recurrence after adhesiolysis, offering novel design ideas for developing biomaterials to prevent peritoneal adhesion.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Barrier materials for prevention of surgical adhesions: systematic review

BACKGROUND

Postoperative surgical adhesions constitute a major health burden internationally. A wide range of materials have been evaluated, but despite constructive efforts and the obvious necessity, there remains no specific barrier widely utilized to prevent postoperative adhesion formation. The aim of this study was to highlight and characterize materials used for prevention of postoperative surgical adhesions in both animal and human studies.

METHODS

A systematic review was performed of all original research articles presenting data related to the prevention of postoperative adhesions using a barrier agent. All available observational studies and randomized trials using animal models or human participants were included, with no restrictions related to type of surgery. PubMed and Embase databases were searched using key terms from inception to August 2019. Standardized data collection forms were used to extract details for each study and assess desirable characteristics of each barrier and success in animal and/or human studies.

RESULTS

A total of 185 articles were identified for inclusion in the review, with a total of 67 unique adhesion barrier agents (37 natural and 30 synthetic materials). Desirable barrier characteristics of an ideal barrier were identified on review of the literature. Ten barriers achieved the primary outcome of reducing the incidence of postoperative adhesions in animal studies followed with positive outputs in human participants. A further 48 materials had successful results from animal studies, but with no human study performed to date.

DISCUSSION

Multiple barriers showed promise in animal studies, with several progressing to success, and fulfilment of desirable qualities, in human trials. No barrier is currently utilized commonly worldwide, but potential barriers have been identified to reduce the burden of postoperative adhesions and associated sequelae.