Regarding the closing the linea alba – some surgeons were concerned about the failure of the whole wound when part of a continuous suture gave way. If you put in a lock-knot every few sutures (every 8 or so to 15, more closely in the lower abdomen), this should limit failure to a short length.
You can make a lock-knot by pulling a short loop under the last suture and snugging it down, pulling another loop through the first one, and then pulling the needle end of the suture through the second one. (After a while you can make this look very slick!)
As far as I know this is called the Aberdeen knot, maybe because you save using as many sutures where you might use more than one.
If you are worried by the sharp end of the needle (fat patient, nervous assistant, other unfavourable conditions), grip the sharp end of the needle in the jaws, pointing to the joint of the needleholder. This also decreases snagging.
Nobody said just how loose a loose suture was, how many to the cm. or inch, how far they set them back (?near and far – me sometimes where the tissues seem cruddy), or whether the sutures are oblique, picking up more or less rectus, anterior or posterior sheath or go through the layer at a right angle.
The relation of tension to wound failure was studied (Br. J. Surg) by Jenkins from a large midlands English hospital, encouraged by Hugh Dudley. After reaching the end of the incision he went back to the start of the incision and tightened each individual suture to a measured tension, something like 1-2 kg force, or 2-3 pounds weight. Maybe someone has the exact figure. I changed my practice after earlier having worried about tight sutures causing ischaemia of the edge, but wouldn’t suture any other tissues tightly like this (I would take a chance on scalp and occasionally shoulder).
An Aberdeen knot is used for finishing the suture. Sometimes (more with finer suture) it locks in a loose configuration, often you can hear a little click as the knot tips over. Other times (e.g. vicryl in the abdomen) it just won’t behave, even when you let the loops straighten out and try again – nylon which has a little more grip than prolene). Then you just do the usual old-fashioned series of hitches (laid nicely as reef knots) with a loop and the end of the suture.
Everyone develops their personal preferences. Habit is more powerful than [other people’s] logic and often works better because of little nuances in technique. I’ve changed my own technique every few years and even between cases occasionally. I like #1 prolene more than anything else. I also maintain tension on the suture myself. Since then I keep relearning that judgment is more important than trying to be slick.
I have the impression that more incisional hernias come out of teaching hospitals than in community practice, and fewer still from up-market expensive surgery – type of patient, operator, circumstances, feed-back.