Effectiveness of barrier agents for preventing postoperative bowel obstruction after laparoscopic surgery: a retrospective cohort study

Physical and biological properties of a novel anti-adhesive punctate uneven gelatin film

Since abdominal adhesion are quite problematic in abdominal and pelvic surgery, the conventional HA/CMC film are commonly used as an anti-adhesive material. However, such types are difficult to be rolled and delivered through the port of laparoscopic surgical devices due to adherence to the laparoscopic port or other parts of the films. To create an anti-adhesion film with more favorable handling properties and anti-adhesive effect, we developed a novel punctate uneven gelatin film (PU GF). In this study, we examined the physical strength, flexibilities and adhesiveness between film to tissues or film each other, compared to the conventional film and the flat gelatin film (Flat GF). In addition, we investigated the cell proliferation on each film and the anti-adhesive effect of the films and those reattachment possibility using a rat cecum abrasion model. The PU GF showed excellent tensile strength, ductility, and adherence to tissue compared to Flat GF and the conventional film. Moreover, the adherence of PU GF to the other film and to a silicon sheet were much lower than those of the Flat GF and conventional film. The proliferation of cells in PU GF and Flat GF were suppressed compared with control, though increased with time. The anti-adhesive scores of the PU GF after one time and re-attachment were significantly higher than that of non-covered control, although there was no significant difference between that of the conventional film and control. Our findings suggest that PU GF improve handling properties of laparoscopic surgery as it has excellent physical strength, ductility, and adherence to tissue, and low adherence to trocar. In addition, the punctate film may be more useful with the re-attachability without tearing and to retained sufficient anti-adhesion effect.

Human placental stem cell-based therapies for prevention of abdominal adhesions: A prospective randomized preclinical trial

BACKGROUND

Abdominal adhesions are networks of fibrotic tissues that form between organs postoperatively. Current prophylactic strategies do not reproducibly prevent adhesive small bowel obstruction across the entire abdomen. Human placental-derived stem cells produce an anti-inflammatory secretome that has been applied to multiple fibrosing diseases. The purpose of this project is to test human placental stem cell (hPSC)-based therapies for prevention of abdominal adhesions in a clinically relevant rat model.

METHODS

Fifty-four (n = 54, n = 6/group) male Sprague-Dawley rats (250-350 g) underwent model creation and treatment randomization under anesthesia. Experimental groups included human placental-derived stem cells (hPSC, 5 × 106 cells/10 mL Plasmalyte A), human placental-derived stem cells in a hyaluronic acid (HA-Mal-hPSC) hydrogel, the human placental-derived stem cell secretome from conditioned media in 10 mL Plasmalyte A, human placental-derived stem cells' conditioned media in a hyaluronic acid (HA-Mal-CM) hydrogel, Plasmalyte A (media alone, 10 mL), hyaluronic acid hydrogel alone (HA-Mal), Seprafilm (Baxter, Deerfield, IL), and the control groups, model with no treatment (MNT) and sham animals. Treatments were administered intraperitoneally, and the study period was 14 days postoperation. Adhesions were scored at necropsy and analyzed as the difference between means of an index statistic (Animal Index Score) versus MNT. Underlying molecular mechanisms were explored by functional genomic analysis and histology of peritoneal tissues.

RESULTS

Hyaluronic acid hydrogel alone, HA-Mal-CM hydrogel, and Seprafilm significantly reduced the overall appearance of abdominal adhesions by mean Animal Index Score at 14 days versus MNT. Human placental stem cell, HA-Mal-hPSC hydrogel, HA-Mal-CM hydrogel, HA-Mal hydrogel alone, and Seprafilm significantly reduced the collagen content of injured peritoneal tissues. Human placental stem cell and HA-Mal-hPSC hydrogel suppressed expression of the most profibrotic genes. Conditioned media, HA-Mal hydrogel alone, and media alone significantly altered the expression of proteins associated with peritoneal fibrotic pathways.

CONCLUSION

Human placental stem cell-based therapies reduce abdominal adhesions in a prospective randomized preclinical trial. This effect is supported by suppression of profibrotic genomic and proteomic pathways.

What Should I Use? Impact of Adhesion Barriers on Postoperative Abdominal Complications: A Systematic Review

BACKGROUND

Adhesions are a feared complication of abdominal surgery. There have been many new adhesion barriers developed and tested; however, there is no recent systematic review analyzing all the published literature. To address this, we aimed to analyze the different types of adhesion barriers, and determine their effects on postoperative outcomes in patients.

METHODS

A total of 14,038 articles utilizing adhesion barriers in abdominal surgery were retrieved from the PubMed, EMBASE, and Scopus databases. Inclusion criteria were: patients undergoing abdominal surgery, patients receiving an adhesion barrier, and reported postoperative outcomes. Two reviewers independently screened titles/abstracts and full-text articles using Covidence. The ROBINS-I tool was used to assess the quality of the included studies. Study protocol: Prospero CRD42023458230.

RESULTS

A total of 20 studies, with no overall high risk of bias, with 171,792 patients were included. Most studies showed an equivocal benefit for adhesion barriers, with no singular adhesion barrier type that had definitive superior outcomes compared to the others. Bioresorbable barriers emerged as the most extensively researched adhesion barrier type, exhibiting promising results in colorectal surgery. Starch-based adhesion barriers also exhibited a reduction in overall postoperative bowel obstructions and may be beneficial for stoma sites and port closures. On the other hand, many studies raised concerns regarding complications, including risk of abscess formation, fistula development, peritonitis, and anastomotic leakage.

CONCLUSIONS

Adhesion barriers should be considered on a case-by-case basis, however, they should not be utilized prophylactically in all abdominal surgeries due to their risk of complications.

Laparoscopic application of sodium hyaluronate-carboxymethylcellulose barrier in abdominopelvic surgery: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Systematic Review Protocols-compliant systematic review and meta-analysis

BACKGROUND

We aimed to evaluate the incidence of postoperative adhesion formation and adhesion-related consequences (eg, bowel obstruction) after placement of a sodium hyaluronate-carboxymethylcellulose adhesion barrier after laparoscopic abdominopelvic surgery.

METHODS

In this systematic review and meta-analysis, we searched the Medical Literature Analysis and Retrieval System Online and Embase via Ovid, Cochrane Central Register of Controlled Trials, ScienceDirect, BIOSIS Previews, Cumulative Index to Nursing and Allied Health Literature, and Clinical Trial Registries. A manual search (eg, Google Scholar and professional association websites) was also conducted to supplement the electronic database results. Two reviewers independently identified relevant studies based on inclusion and exclusion criteria and extracted data.

RESULTS

A total of 28 studies were included in the systematic qualitative review. Three of the 28 studies included had comparable outcome measures, interventions, and control groups, allowing the pooling of study data. A total of 938 patients (490 patients in the sodium hyaluronate-carboxymethylcellulose barrier group and 448 in the no adhesion barrier group) from these 3 studies were included in the meta-analyses, which found the incidence of bowel obstruction was significantly lower (65% risk reduction) in the sodium hyaluronate-carboxymethylcellulose barrier group compared with the control group (relative risk = 0.35; 95% confidence interval, 0.19-0.63; P = .005) with extremely low heterogeneity between studies (I2 = 0; P = .41). The placement of sodium hyaluronate-carboxymethylcellulose barrier laparoscopically did not create new safety signals nor did it increase the incidence of adverse events.

CONCLUSION

Our meta-analysis found that laparoscopic application of a sodium hyaluronate-carboxymethylcellulose barrier in abdominopelvic surgery reduces the risk of bowel obstruction where applied during the early postoperative phase.

Risk factors for small-bowel obstruction after colectomy for colorectal cancer: a retrospective study

PURPOSE

Postoperative adhesions are a concerning complication of abdominal surgery with major implications on quality of life. This study aimed to investigate the risk factors for postoperative small-bowel obstruction (SBO) after colectomy for colorectal cancer.

METHODS

We reviewed the clinicopathological variables of 1646 patients who underwent colectomy for colorectal cancer between 2009 and 2018.

RESULTS

SBO occurred following primary tumor resection for colorectal cancer in 67 (4.1%) of the 1646 patients. The median observation period was 7.5 (range: 3.0-12.0) years. Multivariate analysis revealed that rectal tumors, anastomotic leakages, previous abdominal surgeries, and longer operating times were all correlated with postoperative SBO, but there were no differences in the incidence of SBO between laparoscopic vs. open surgery. The use of adhesion prevention material had no effect on SBO. Our data showed that the onset of SBO tended to be relatively early, within a year after surgery (89.5%).

CONCLUSIONS

Tumor localization in the rectum is associated with several problems, including a wide resection area, prolonged operative duration, and high risk of anastomotic leakage, which may increase the risk of SBO. Laparoscopic surgery and adhesion prevention material did not demonstrate a clear preventive effect against SBO.

A Seven-Year Etiological Study of Adult Bowel Obstruction in Shiraz, Iran

BACKGROUND

Bowel obstruction is a disorder in the passage of bowel contents, the etiology of which varies depending on temporal and geographical conditions. This study investigated the etiology of bowel obstruction in a large number of patients at an adult surgery referral center in southern Iran.

METHODS

In this cross-sectional study, we reviewed the medical records of all patients admitted to Shahid Faghihi hospital (Shiraz, Iran) between 2014 and 2020 with a diagnosis of small or large bowel obstruction. Patients with missing or obscure data on etiology were excluded. Data was collected on the patients' age, gender, history of relevant surgeries, comorbidities, cause of obstruction, site/type of obstruction, treatment, intensive care unit (ICU) admission, length of hospital stay, and outcome. Statistical analyses were made using SPSS v. 25.0.

RESULTS

A total of 2781 bowel obstruction patients (61.4% males, 38.6% females) with a median age of 58 (IQR 43-71) years were studied. Most responded to non-surgical treatment (61.3%). While the obstruction was mostly partial (65.5%), 94.4% of patients with complete obstruction required surgery. Small bowel obstruction (SBO) was almost three times more prevalent than large bowel obstruction (LBO). Adhesion bands were the leading cause of SBO (66.77%), while LBO was primarily due to colorectal tumors (33.9%).

CONCLUSION

The predominant etiology of LBO was colorectal cancer, suggesting that policymakers should improve surveillance programs to detect the condition earlier. Regarding SBO, the leading cause was adhesion bands, indicating the necessity of further efforts to reduce the rate of adhesions following intra-abdominal operations.

Clinical epidemiology and pharmacoepidemiology studies with real-world databases

Hospital-based registry data, including patients' information collected by academic societies or government based research groups, were previously used for clinical research in Japan. Now, real-world data routinely obtained in healthcare settings are being used in clinical epidemiology and pharmacoepidemiology. Real-world data include a database of claims originating from health insurance associations for reimbursement of medical fees, diagnosis procedure combinations databases for acute inpatient care in hospitals, a drug prescription database, and electronic medical records, including patients' medical information obtained by doctors, derived from electronic records of hospitals. In the past ten years, much evidence of clinical epidemiology and pharmacoepidemiology studies using real-world data has been accumulated. The purpose of this review was to introduce clinical epidemiology and pharmacoepidemiology approaches and studies using real-world data in Japan.