The comparison of the suture materials on intestinal anastomotic healing: an experimental study
Executive Summary
This briefing document synthesizes the findings of a prospective experimental study evaluating the impact of different suture materials on the healing of intestinal anastomoses. Conducted using a rat model, the research compared three distinct classes of sutures: absorbable (Vicryl), slowly-absorbable (Polydioxanone/PDS), and non-absorbable (Polypropylene).
The study concludes that the choice of suture material—whether absorbable or non-absorbable, monofilament or multifilament—does not significantly alter the healing process, tissue strength, or inflammatory response. Across all metrics, including anastomotic bursting pressure, tissue hydroxyproline levels, and histopathological scoring, no statistically significant differences were found between the materials. These findings suggest that all three suture types can be utilized safely in intestinal surgery, particularly when combined with meticulous surgical techniques such as microsurgery.
Introduction and Study Rationale
Intestinal anastomosis remains a cornerstone of surgical practice, particularly in pediatric and neonatal surgery where small intestinal diameters may preclude the use of automatic stapling devices. Despite advancements in surgical technology, complications such as leakage, stenosis, and dysfunction continue to contribute to patient morbidity and mortality.
The healing of an anastomosis is influenced by both systemic and local factors. A critical local factor is the choice of suture material, as its structural and absorbable properties can influence tissue reactions and microcirculation. While absorbable and slowly-absorbable materials are commonly preferred, the literature contains varying outcomes regarding their efficacy. This study sought to provide a definitive comparison of physical, biochemical, and histological consequences of these materials on the healing process.
Methodology
The study employed 24 female Wistar Albino rats, divided into three equal groups based on the suture material used for colonic anastomosis:
Group 1 (Vicryl®): Polyglactin 910 (Absorbable).
Group 2 (PDS): Polydioxanone (Slowly-absorbable).
Group 3 (Prolene®): Polypropylene (Non-absorbable).
Surgical Protocol
Under general anesthesia (ketamine and xylazine), a 3 cm median incision was made to perform an end-to-end anastomosis of the ascending colon. The procedure utilized:
Single-layer, full-thickness 6/0 sutures.
10–12 separated knots per anastomosis, placed outside the lumen.
3.5× magnification optical glasses to ensure precision and preserve microvascular perfusion
Evaluation Parameters
The animals were evaluated on the 7th post-operative day through the following metrics:
Clinical Outcomes: Survival, leakage, intestinal obstruction, and wound infection.
Adhesion Score: Macroscopic examination using the Diamond classification.
Anastomotic Bursting Pressure (ABP): An in vitro measurement of the pressure required to cause leakage in the excised segment.
Biochemical Analysis: Measurement of hydroxyproline concentrations (an indicator of collagen synthesis and tissue strength) via ELISA.
Histopathology: Scoring of tissue healing and fibrosis using the Greenhalgh method (scores ranging from 1 for no granulation to 4 for thick granulation and re-epithelialization).
Key Results and Comparative Analysis
All 24 subjects survived the experimental period without complications such as leaks, infections, or weight loss. The following table summarizes the data across the three suture types:
Analysis of Primary Findings
Anastomotic Durability: While the Polypropylene and PDS groups showed numerically higher median bursting pressures than the Vicryl group, the difference was not statistically significant. This indicates that the mechanical integrity of the anastomosis is not compromised by the choice of suture.
Collagen Synthesis: Hydroxyproline levels, which reflect the stability of the structural proteins essential for healing, were highest in the Vicryl group and lowest in the Polypropylene group. However, the lack of statistical significance indicates that all materials support adequate collagen deposition.
Adhesion and Inflammation: The Vicryl group demonstrated numerically lower adhesion scores compared to the other groups, yet all subjects in all groups exhibited some level of adhesion. Histopathological examination confirmed that the inflammatory response and granulation tissue quality were similar across the board.
Safety and Efficacy: The 0% leakage and obstruction rate across the entire cohort suggests that local tissue trauma from the suture material is minimal, especially when microvascular perfusion is preserved.
Discussion and Clinical Implications
The study highlights that the adverse effects of suture materials on intestinal prognosis are very limited. Historically, suture materials have been linked to tissue reactions or microabscesses, but this study demonstrated that modern absorbable and non-absorbable options do not adversely affect wound healing.
Impact of Surgical Technique
The authors attribute the high success rate (absence of leakage and stricture) to the use of microsurgical techniques. By avoiding damage to microvascular perfusion during transection and using magnification for precise suture placement, the negative potential of "foreign body" reactions from the sutures was mitigated.
Suture Selection Flexibility
The findings challenge the strict preference for absorbable materials in intestinal surgery. The data suggests that surgeons may select suture materials based on availability, handling preference, or specific clinical situations (such as neonatal surgery) without fear of compromising the integrity of the anastomosis or the healing process.
Conclusion
This experimental study confirms that suture material choice is not a primary determinant of intestinal anastomotic success. Absorbable (polyglactin), slowly-absorbable (polydioxanone), and non-absorbable (polypropylene) sutures all demonstrated comparable performance in terms of tissue healing, bursting pressure, and biochemical markers. Consequently, all these materials can be used safely in clinical practice for intestinal anastomoses.
