BENIGN PROSTATE SURGERY IV TRANSURETHRAL
Transurethral resection of the prostate (TURP) is currently the most popular approach for the surgical treatment of benign prostatic hyperplasia (BPH). It has the advantage of being an endoscopic procedure that avoids an abdominal or perineal incision and is associated with earlier ambulation and faster convalescence than the “open” approaches. It is appropriate for the treatment of small to moderate size (75 g) prostatic enlargement and is technically more sophisticated than the open surgical procedures. With benign prostatic enlargement, the objective is complete removal of the adenomatous tissue to the surgical (false) capsule, but in cases of urethral obstruction due to advanced prostatic cancer, a “channel” TURP is performed to reestablish urethral patency.
The TURP was developed in the 1920s after the invention of incandescent
light, the cystoscope, and high-frequency electrical current. It is considered
the standard for the surgical treatment of BPH. Classically, transurethral
prostatectomy employs a wire loop through which a high-frequency current is
used to cut and coagulate tissue. The resectoscope is operated entirely by one
hand, leaving the other hand free for insertion of a finger into the rectum to
elevate the prostate. With the patient in lithotomy position, the penile
urethra is calibrated with a bougie á boule to ensure that it is sufficient in
size to accept a large cystoscope. If it is not, the cystoscope can be inserted
through a perineal urethrostomy into the more commodious bulbar urethra. To
reduce back strain on the surgeon, a video camera is commonly used to visualize
the procedure.
Adenoma resection should be performed in a step-wise, orderly fashion and
typically begins at the bladder neck as described by Nesbitt. The adenoma is
resected at the bladder neck around its circumference until the circular fibers
of this structure are visible. Many surgeons also resect the intravesical
median lobe at this point (as illustrated), to increase irrigant flow and
overall visibility for the remainder of the procedure. Next, one of the lateral
lobes is chosen for resection. The resectoscope is placed immediately proximal
to the verumontanum to minimize damage to the external urethral sphincter and
tissue resection starts at the 12-o’clock position to allow the remaining
lateral lobe tissue to “fall into” the prostatic fossa. With each excursion of
the cutting loop, a “boat-shaped” piece of adenomatous tissue is cut away and
allowed to fall into the bladder. Bleeding is controlled by application of a
hemostatic current through the wire cautery loop. Resection proceeds to the
6-o’clock position and is carried down to the false or surgical capsule, which
appears more fibrous than the granular adenoma. The other lateral lobe is then
similarly approached. The final part of the procedure involves careful tissue
removal from the floor of the prostate and from the prostatic apex near the
external sphincter while preserving the verumontanum. At the end of the
procedure, accumulated tissue in the bladder is aspirated through the sheath of
the instrument, followed by the insertion of a Foley catheter. The catheter
remains in place for 24 to 48 h and obstructing blood clots are minimized with
continuous bladder irrigation if needed.
Sequelae of TURP include bleeding requiring transfusion or reoperation,
urethral or bladder neck strictures, retrograde ejaculation, incontinence, and
erectile dysfunction. Dilutional hyponatremia (TURP syndrome) occurs in 2% of
cases when isotonic water is used as an
irrigant and results from systemic absorption of water as a consequence of
prolonged (1.5 hours) resection time, resection of large glands, or early
penetration of the surgical prostatic capsule. The syndrome is characterized by
confusion, nausea, vomiting, hypertension, bradycardia, and visual disturbance
and can be lethal if not carefully treated with 3% saline solution and
diuresis.
Recent variations on the classic TURP include the use of bipolar instead
of monopolar electrocautery that can be used with saline irrigation instead of hyponatremic water. Methods that employ tissue vaporization (TUVP) and
desiccation, as well as laser-induced destruction of tissue (Nd: YAG, KTP,
holmium, and diode), in lieu of fulguration have also been developed to reduce
hematuria and catheterization time. Many minimally invasive methods of treating
BPH have also been described that may reduce the adverse effects of TURP but do
not appear to offer the same quality or durability. These include
intraprostatic stents, transurethral needle ablation of the prostate using
radiofrequency energy, and transurethral microwave therapy.
