Small bites versus large bites for closure of abdominal midline incisions (STITCH): a double-blind, multicentre, randomised controlled trial
Executive Summary
The STITCH trial (Small Tissue Bites versus Large Bites for Closure of Abdominal Midline Incisions) was a multicenter, double-blind, randomized controlled trial conducted across ten hospitals in the Netherlands. The study aimed to compare the effectiveness of a "small bites" suturing technique against the traditional "large bites" technique in preventing incisional hernias—a frequent and costly complication of midline laparotomy.
Critical Findings:
Reduced Hernia Incidence: At a one-year follow-up, 13% of patients in the small bites group developed an incisional hernia, compared to 21% in the large bites group (p=0.0220).
Safety Profile: There were no significant differences between the two groups regarding adverse events, surgical site infections, or postoperative pain.
Procedure Efficiency: While the small bites technique increased the mean closure time by four minutes (14 minutes vs. 10 minutes), it resulted in a higher suture length to wound length ratio (5.0 vs. 4.3).
Clinical Recommendation: Based on the significant reduction in hernia occurrence without increased morbidity, the study concludes that the small bites technique should become the standard of care for closing midline abdominal incisions.
Background and Clinical Rationale
Incisional hernia is a major complication of abdominal surgery, with an incidence rate typically between 10% and 23%, rising as high as 38% in high-risk populations. In the United States alone, approximately 400,000 to 500,000 incisional hernias occur annually, leading to:
Decreased Quality of Life: Associated with pain, discomfort, and mobility issues.
Medical Risks: Potential for incarceration and strangulation of abdominal contents, requiring emergency surgery.
Economic Burden: Estimated annual costs for incisional hernia repairs in the USA reach $3.2 billion.
While meta-analyses previously established that a running technique with long-lasting monofilament suture is superior to interrupted sutures, most surgeons continued to use large tissue bites (1 cm or more). The STITCH trial sought to validate earlier Swedish findings suggesting that smaller, more frequent stitches could better distribute force and promote healing.
Methodology and Trial Design
The trial included 560 patients (284 large bites, 276 small bites) scheduled for elective abdominal surgery through a midline incision between 2009 and 2012.
Suture Techniques Compared
The trial meticulously standardized the two techniques to ensure a clear comparison:
Assessment Protocols
Double-Blind Design: Both patients and study investigators were masked to the group allocation.
Primary Outcome: Presence of incisional hernia at one year, defined by the European Hernia Society as any abdominal wall gap or bulge perceptible by clinical examination or imaging.
Imaging: The study prioritized radiological imaging (ultrasonography or CT), as physical examinations often miss smaller defects.
Analysis of Key Findings
Primary Outcome: Hernia Incidence
The small bites technique demonstrated a clear statistical advantage in preventing hernias:
Small Bites Group: 35 of 268 patients (13%).
Large Bites Group: 57 of 277 patients (21%).
Statistical Weight: The covariate-adjusted odds ratio was 0.52 (95% CI 0.31–0.87; p=0.0131).
Secondary Outcomes and Complications
The study found no detrimental impact from the increased number of stitches in the small bites group:
Postoperative Complications: 45% in both groups.
Surgical Site Infection (SSI): 21% (small bites) vs. 24% (large bites); difference not significant.
Burst Abdomen: Occurred in 1% of both groups, confirming that the thinner 2-0 suture is sufficiently strong for fascial closure.
Pain and Quality of Life: Visual analogue scale (VAS) pain scores in the first postoperative week and SF-36 quality of life scores at 12 months showed no significant differences between the two techniques.
Procedural Metrics
The small bites technique required more precision and time:
Number of Stitches: Mean of 45 (small) vs. 25 (large).
Closure Time: Mean of 14 minutes (small) vs. 10 minutes (large).
Suture Ratio: The small bites group achieved a higher suture-to-wound length ratio (5.0 vs 4.3), which is a known factor in reducing wound failure.
Clinical Implications and Conclusions
The Role of Medical Imaging
The trial highlighted the necessity of radiological assessment in postoperative follow-up. Of the hernias identified, 47% were detected solely through radiological examination. Relying only on physical examination would have significantly underestimated the complication rate.
Theoretical Advantages of Small Bites
The researchers hypothesize that the small bites technique provides ideal conditions for fascial healing by:
Avoiding Necrosis: By taking smaller bites of the aponeurosis and avoiding muscle/fat, the technique prevents tissue strangulation.
Force Distribution: Increasing the number of stitches leads to a more equal distribution of tension across the wound.
Collagen Optimization: Experimental data suggests that reduced tensile force per suture results in a better ratio of collagen type 1 to type 3, leading to stronger scar tissue.
Final Conclusion
The STITCH trial provides "strong evidence" that the small bites suture technique is superior to the traditional large bites approach for midline laparotomies. It significantly reduces the incidence of incisional hernia without increasing the risk of adverse events or causing additional postoperative pain. The study concludes that the small bites technique (5 mm bites every 5 mm) should be considered the standard closure technique for midline incisions.
