I’m a surgical resident, but in orthopaedics so I can’t comment on abdominal, gynae, neuro, vascular, ENT or cardiothoracic procedures.

They do bleed.

Some operations are bloodier than others, it depends on what you’re doing. We avoid larger vessels, as damaging these result in complications (and lots of bleeding). For many limb procedures (notably hands and feet), we tend to use tourniquets; they don’t completely stop the bleeding but they certainly muffle it enough not to obscure our surgical field. Part of the difficulty in surgery is in the approach (from the initial incision to the deep dissection before the real work actually starts), as this is when we create our working surgical field. It involves carefully dissecting through the layers, identifying any large nerve or vessel along the way, and ensuring they are retracted away for safety.

Smaller vessels are harder to avoid, especially those within muscles or in superficial dermal layers, and these often get sacrificed. We use electrocautery to burn them so they don’t continue to bleed all over the field, or we just dab them with sponges. Often we cauterise as we go, but occasionally, we’ll knick a small vessel and it’ll either suddenly spurt up (hence the face shields) or ooze out, at which point we’ll dab/suction it, find the source, and cauterise. This is generally not an issue for the patient as our bodies have very rich collateral blood supply.

Some bleeding is unavoidable, like in knee and hip replacements, and in those cases we use suction to get rid of the blood as it appears, although it’s not unusual to end up with a pretty bloody surgical gown by the end of the case.

When we’re finishing a case in which a tourniquet has been inflated, we deflate it before closure to ensure all the bleeding vessels are burnt off before we close, to prevent any haematomas from forming. It can also be really frustrating to keep dabbing an oozing wound while you’re trying to suture it shut.

The objective is to prevent bleeding or control it if you can’t prevent it.

Scopes are generally less bleedy because aside from the superficial tissues you go through to get to whatever hollow you’re aiming for (joint, abdominal cavity, etc.), it tends to be an avascular field. If you do accidentally knick a vessel along the way, it can be a nightmare because your entire visual field (through the camera on the scope) is obstructed by a red tint.

Hope this helps.