I believe both procedures remove a substantial amount of prostate tissue.
The idea is to really open up that channel and to keep it open for years.  I
think the amount of work in the bladder neck area depends on which lobes are
enlarged.  Bladder neck damage often results in retrograde ejaculation.

Liz,
I'll do my best to answer your question.

1. The prostate is a gland with fibrous smooth muscle tissue on the outside
and glandular tissue on the inside.

2. BPH causes the prostate to enlarge from the inside as the glandular
tissue grows and tries to expand. This closes off the urethra and pushes
upward against the bladder.

3.  PVP's laser wavelength at 532 nanometers vaporizes this glandular tissue
quite well but it doesn't do a good job on the outer smooth muscle/ fibrous
tissue.

4. So the surgeon takes the PVP fiber into the urethra and blasts outward.
He takes out all the inside glandular tissue of the prostate, stopping when
he gets to  the outer capsule. He should know from experience that once
laser is have a tougher time vaporizing tissue that he is near the outer
capsule.

5. The surgeon's skill is tested if the prostate has grown into the bladder
at the bladder neck.  He needs to remove prostate tissue but leave bladder
muscle, a very difficult and time consuming process.  This is where the
skill and patience comes in.  If too much bladder neck muscle is removed,
retro is likely.  If not enough prostate tissue is removed from the bladder
neck, symptom relief won't occur and the remaining glandular tissue
continues to grow.

So the amount of prostate tissue removed depends on how large the prostate
is and if it is grown into the bladder.  But if the prostate is the size of
a mandarin orange, the goal of PVP is to get all the insides out leaving the
orange skin intact.

I hope this explanation helps.

Regards,
Patrick
PVP June 2002 (first on this newsgroup)
Dr. Te NY