Veins Still There After Laser?

You did not post pictures which would have been helpful in providing you better guidance ...I am assuming that these thread veins are on the legs or lower extremities. KTP lasers were described as early as 1999 in published literature to be beneficial in treating telangiectasias of the face and legs. I find that in > 95% of cases that sclerotherapy is effective because it not only treats the telangiectasias but also the 'feeder veins'. Not adequately treating these 'feeder veins' is the reason for lack of success of the KTP laser technique. 

From your description, it does sound as if most of the veins did not respond to the KTP laser.  You are correct, i.e. if you can still see blood moving out of the veins when you press on them, then the veins are still alive and did not respond to the laser treatment.  We have seen many patients in our practice that get poor response or minimal response to KTP laser treatment for spider veins of the legs.  I find it to be a more effective treatment when used on facial spider veins.  It is less effective for larger spider veins, but can be effective for the small spider veins, although several treatments are usually needed.

My recommendation for you would be to consider sclerotherapy treatment for spider veins . . . this is a much more common therapy for leg spider veins and I find it to be extremely effective and well tolerated by patients.  The other option is to use a more "vein specific" surface thermal treatment, such as use of the Veinwave or Veingogh device, which I have also had alot of success with.  Seek our a vein specialist in your region that has experience with these therapies.  I am confident that you can get the results you are looking for by going with a different treatment modality.

it can take many weeks for blood vessels in the legs to respond to laser treatment. Multiple sessions are necessary. At this point in time the treatment of leg veins is still felt to be best treated by sclerotherapy

Most treatments for spider veins require mutliple sessions to achieve success.  One treatment will rarely get rid of all spider veins.  Since spider veins vary in size, some may require more total energy to dissolve them. It is not uncommon for spider vein to take time to dissolve.  After the initial treatment with either a laser or even sclerotherapy, It may take several weeks for the treated veins to show the effects of the laser or injection.  You should return for further treatments.