Author: Dr Tony Williams, Consultant Occupational Physician, Working Fit Ltd.
Date: August 2015.
Wounds are closed to ensure efficient swift healing. Simple facts such as the dexterity of the surgeon or the technique used can substantially affect healing times and long term results.
A review of laparotomy technique showed significantly lower rates of incisional hernia using single layer closure with continuous technique and slowly absorbable sutures. There was no difference in incisional hernia rates comparing absorbable and non-absorbable sutures. There was a decrease in incisional hernia rates if a suture length to wound length ratio of four or more and short stitch lengths were used (Meijer et al., 2013).
Long-lasting sutures and mesh grafts are foreign bodies, so ideally should be avoided. They are only used where there will be delayed healing or longer term weakness. Traditional absorbable sutures will only provide good support for two or three weeks, holding the wound together only long enough for wound remodelling to start. Newer long-lasting suture materials such as polydioxanone maintain tensile strength for around eight weeks, allowing for remodelling to achieve good strength, with full absorption taking around six months. Where longer-term structural integrity is required, non-absorbable materials may be used. These can be sutures of polypropylene in soft tissue or wire in bone. Where large areas of support are required, polymer mesh or tape is often used. While skin closure with staples, clips or sutures is unlikely to add substantially to wound strength, the addition of sutured mesh or tape will provide immediate strength and support.
Tissue reaction in a rabbit model to tension-free vaginal tape sling materials showed marked acute inflammation on days 2 to 7, with stable fibrosis and muscle infiltration on day 30 (Yildirim et al., 2005).
Strength of tissue attachment to composite and ePTFE mesh in porcine models showed 74% strength at two weeks for composite polypropylene/ePTFE and peak strength in ePTFE at two weeks (Iannitti et al., 2007).
A review of 3125 consecutive hernia repairs by open tension-free mesh showed a recurrence rate of four, all due to technical errors early in the study (Amid et al., 1993).
These studies suggest that tape and mesh take about two weeks to embed in the tissues and probably take four weeks to full strength. The technique in inguinal hernia repair would indicate that the strength of mesh and sutures is sufficient to allow full physical activity immediately after surgery without risk of recurrence. In the case of other hernia repairs and gynaecological surgery with tape, full strength can be assumed after four weeks.