Fluid and pharmacological agents for adhesion prevention after gynaecological surgery

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

BACKGROUND

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

METHODS

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

RESULTS

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

DISCUSSION

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

Comparison of the effect of Everolimus, Prednisolone, and a combination of both on experimentally induced peritoneal adhesions in rats

Postoperative intra-abdominal adhesions represent a significant post-surgical problem. Its complications can cause a considerable clinical and cost burden. Herein, our study aimed to investigate the effect of Everolimus on peritoneal adhesion formation after inducing adhesions in rats. In this experimental study, adhesion bands were induced by intraperitoneal injection of 3 ml of 10% sterile talc solution in 64 male albino rats. The first group served as the control group. The second one received oral Prednisolone (1 mg/kg/day), the third received Everolimus (0.1 mg/kg/day), and group four received both drugs with similar dosages for four consecutive weeks. The formation of adhesion bands was qualitatively graded according to the Nair classification. The rats in the control group had extensive adhesions between the abdominal wall and the organs. Regarding substantial adhesion formation, 50% (8/16) of animals in the control group had substantial adhesions, while this rate in the groups receiving Prednisolone, Everolimus, and combination treatment was 31%, 31%, and 31%, respectively. Also, 68.75% (5/11) of the Prednisolone recipients had insubstantial adhesions, the same as Everolimus recipients, while in the combination group, 66.66% (10/15) rats had insubstantial adhesions. Everolimus demonstrated satisfactory results in reducing the rates of induced peritoneal adhesion in an experimental model, similar to Prednisolone and superior to a combination regime.

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.

Obstrucción intestinal por adherencias: un lienzo en blanco en el que el cirujano elige los colores

Introducción. La obstrucción intestinal es una patología de alta prevalencia. Su abordaje diagnóstico y terapéutico ha evolucionado acorde con el avance del conocimiento e implementación de la tecnología. El impacto de sus complicaciones obliga a redoblar esfuerzos en pro de lograr una mayor efectividad. Se hizo una aproximación reflexiva al problema, mediante una identificación de los puntos controversiales de interés para el cirujano general. Métodos. Se realizó una búsqueda sistemática de la literatura en varias bases de datos, utilizando dos ecuaciones de búsqueda que emplearon términos seleccionados a partir de los tesauros “Medical Subject Heading” (MeSH) y “Descriptores en Ciencias de la Salud” (DeCS). Resultados. Se recolectaron 43 artículos y a partir de ellos se construyó el texto de revisión. La identificación pronta de los posibles candidatos a cirugía, mediante un esquema diagnóstico y terapéutico, se constituye en una prioridad en el manejo de estos pacientes. De igual manera, se efectúan consideraciones en la toma de decisiones con respecto a la vía quirúrgica, así como recomendaciones técnicas operatorias producto de la experiencia y lo reportado en la literatura. Existen factores propios del cirujano, del contexto y del paciente, que inciden en la resolución del problema. Conclusión. La obstrucción intestinal y sus implicaciones clínicas obligan a una reevaluación constante de su estado del arte y avances en el manejo, tendiente a una búsqueda de oportunidades para impactar favorablemente en su curso clínico. Hay estrategias por implementar, inclusive el manejo laparoscópico en casos seleccionados.

Liquid-Liquid Phase-Separated Hydrogel with Tunable Sol-Gel Transition Behavior as a Hotmelt-Adhesive Postoperative Barrier

Postoperative barriers have been widely used to prevent adhesions. However, there are currently few barriers that satisfy clinical requirements, such as tissue adhesion, operability, and biocompatibility. Inspired by the adhesion system of living organisms, we report a liquid-liquid phase-separated hydrogel as a single-syringe hotmelt-type postoperative barrier. Mixing polyethylene glycol with gelatin formed liquid-liquid phase-separated hydrogels through segregative liquid-liquid phase separation. Incorporation of a liquid-liquid phase-separated system into gelatin can enhance the sol-gel transition temperature to give a hotmelt-adhesive property to hydrogels. Hotmelt-adhesive hydrogels became a sol phase and cohered into tissue gaps when warmed and solidified at body temperature to adhere to soft tissues. The hydrogels exhibited tissue adhesion to large intestine tissues and showed improved mechanical strength, gelation time, and shear-thinning properties. In rat cecum-abdominal adhesion models, it was confirmed that the resulting hydrogels prevented abdominal adhesion and did not prevent tissue regeneration. Hotmelt-adhesive hydrogels with high tissue adhesive properties, operability, and biocompatibility have enormous potential as barriers to prevent postoperative complications.

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

PURPOSE

The effectiveness of using anti-adhesion agents in laparoscopic surgery is controversial. We compared the outcomes of patients exposed to anti-adhesion agents (barrier group) with those of patients not exposed (no barrier group) in laparoscopic surgery.

METHODS

Using a nationwide claim-based database in Japan, we analyzed data from patients who underwent laparoscopic surgery between 2005 and 2019 and compared the patient characteristics and the proportion of those with bowel obstruction between the barrier and no barrier groups. We also performed several sensitivity and subgroup analyses.

RESULTS

Of the 57,499 patients who met the inclusion criteria, 14,360 and 43,139 were assigned to the barrier and no barrier groups, respectively. The proportion of patients with a bowel obstruction in the two groups did not differ among all patients hospitalized for obstruction (1.1 vs. 1.1%, p = 0.63) and those requiring surgery (0.2 vs. 0.2%, p = 0.39). In the sensitivity analysis with propensity score matching, the incidences of bowel obstruction between the barrier and non-barrier groups were equivocal (1.3 vs. 1.6%), but statistically marginal (chi-square test, p = 0.035; log-rank test, p = 0.09).

CONCLUSION

The use of barrier agents for adhesive prevention did not show clear effectiveness for the prevention of bowel obstruction after laparoscopic surgery for unselected cases. Further studies focusing on more specific procedures are needed.

Growth factors in the regulation of reparative response in the presence of peritoneal damage

Objectives

To study the expression of growth factors in the regulation of tissue repair after peritoneal damage tissue response to peritoneal damage.

Methods

Experimental study in 35 male Wistar rats determining the evolution over time of the tissue response to aseptic peritoneal damage. A standardized bowel and peritoneal lesions were created in the right lower quadrant by laparotomy. Then, tissular expression of growth factors was evaluated by multiplex polymerase chain reaction at seven timepoints between 6 h and 30 days, postoperatively.

Results

Tissular responses of granulocyte-stimulating factors (Csf2, Csf3), connective tissue growth factor (Ctgf), epidermal growth factors and receptor (Egf, Egfr), fibroblast growth factors (Fgf2, 7 and 10), heparin binding EGF-like growth factor (Hbegf), hepatocyte growth factor (Hgf), insulin-like growth factor-1 (Igf1), mitogenic transforming growth factors (Tgfa, Tgfb1, Tgfbr3), and vascular endothelial growth factor A (Vegfa) were biphasic with a first expression peak at day 3, followed by a more pronounced peak at day 14.

Conclusions

We observed a long-lasting, widespread response of tissular growth factors for at least two weeks after peritoneal damage. To be clinically effective, the prophylaxis of postoperative adhesions might be needed for an extended period of time.

Mini-Review of the New Therapeutic Possibilities in Asherman Syndrome-Where Are We after One Hundred and Twenty-Six Years?

Asherman syndrome is a multifaceted condition describing the partial or complete removal of the uterine cavity and/or cervical canal. It is a highly debatable topic because of its pronounced influence on both reproductive outcomes and gynaecologic symptoms. The latest reports demonstrated that trauma to the endometrium is the main cause of intrauterine adhesion formation. Left untreated, such adhesions gradually lead to a range of repercussions ranging from mild to severe. Considering the lack of non-invasive approaches, the advent of hysteroscopy has revolutionized the entire field, being otherwise considered the most efficient tool offering new directions and amplifying the chances of treating the Asherman syndrome.