What do they do if a wound is too deep or too wide to stitch?

Depends on the wound: A deep wound can be sutured in several layers. Wound that is too wide is sometimes left to heal on its own or plastics surgeons will use a flap. An infected wound is usually left open to heal by itself.

Wound Closure: If you have a wound that you believe is too deep or wide, you should be seen by a professional either in an emergency dept or urgent care setting. I cannot think of a wound too deep. If it is a deep wound, it can be sutured in layers. As for too wide, wounds to wide can be approximated and closed by secondary intention or may even require a skin graft.

Wound care: See a wound care doctor. With good nutrition and care it will close.

Heals from inside ou: Wound is left open to heal from inside out - sometimes with a help of wound vac.

Laser treatment: In one of my cme course at harvard medical school, 'structural acupuncture for physician' they have mentioned that laser beam at certain wave length helps wound healing. I have tried on not so deep, but more than skin thickness, involving fascia did heal quicker. But I have not attempted on larger and deeper wounds.

Age? Cause?: A wound may be too old to stitch also. In wound care we encourage a wound to fill itself by carefully controling how moist it is and protecting it with many possible dressings possibly including suction. A simple but deep one may need deep and superficial sutures while a surgeon may essentially change the alignment of parts of a wider area of tissue to enable closure . Called flapping or bring.