Urinary obstruction

By Dr Mário Apolinário [email protected]

Dr Mário Apolinário is a Specialist Urologist, member of the Team of Urologists of Hospital Particular do Algarve

For most of the 20th century, from 1909 when Hugh Hampton Young performed his first blind cold-cut prostatic punch operation, until the late 1990s when effective medical therapy and newer, less invasive technologies for prostatic obstruction were developed, the premier treatment for symptomatic benign prostatic hypertrophy (BPH) was transurethral resection of the prostate (TURP). It was the first successful, minimally invasive surgical procedure of the modern era.

Urinary obstruction from prostatic hypertrophy has been described for many centuries, starting with the Egyptians in the 15th century BC. The word “prostate” comes from the Greek prostat, which means “one who stands before or in front of”, which in this case means in front of the bladder.

The prostate is probably the organ of the body most likely to be involved with disease in men older than 60 years. As the hyperplastic androgen-dependent process increases the volume of the prostate, the urethral lumen is compressed, causing bladder outlet (fig 1) obstruction.

Classic symptoms of BPH include a slow, intermittent, or weak urinary stream, the sensation of incomplete bladder emptying, double voiding (the need to void within a few seconds or minutes of urinating), postvoid dribbling, urinary frequency and nocturia. Patients may also present with acute or chronic urinary retention, urinary tract infections, gross hematuria, renal insufficiency, bladder pain or incontinence. Symptoms are not related to the size of the prostate on digital rectal or transrectal ultrasound findings.

The goal of prostate surgery for BPH is to remove the obstructing tissue while minimising damage to surrounding structures, with little discomfort to the patient.

The accessibility of the obstructing prostate via transurethral endoscopy affords the opportunity to remove the obstruction without open surgery (fig 2). Electrical cautery that could work underwater was first demonstrated by Beer in 1909, when it was used on bladder tumours.

The first successful continuous-flow resectoscope was reported by Iglesias in 1975, but only at mid 1990s, practical continuous-flow resectoscopes became popular and widely available.

Modern coaxial continuous-flow bipolar resectoscopes are currently the overwhelming first choice of urologists for TURP instrumentation.

Newer therapies are introduced that hope to match the long-term symptom relief success of TURP, while reducing the already low morbidity allowing short hospitalisation periods (24-48h).

Currently, these techniques include PVP laser ablation and bipolar TURP.

Photoselective vaporisation of the prostate (Greenlight laser)

Photoselective vaporisation of the prostate (PVP) uses a high-power potassium-titanyl-phosphate (KTP) laser, also called the “greenlight” laser. KTP laser energy only penetrates 1-2 mm deep into the prostatic tissue (fig 3), making it superior to other types of prostatic laser vaporisation procedures. Modern KTP laser vaporises the prostatic tissue fairly rapidly. The limited tissue penetration, compared to other lasers, minimises the adverse side effects.

The PVP/KTP procedure has excellent hemostasis because the blood vessels are rapidly sealed, so significant bleeding is not common. The procedure can be performed quickly and safely, even in patients who cannot be taken off their anticoagulant medications, which is a major advantage over TURP.

Bipolar TURP

The instrumentation and surgical TURP technique are identical except for the special bipolar electrical generator and the specially modified loops and resectoscopes. When the cutting current is applied, a plasma corona is formed cutting effectively the tissue. Collateral and penetrative tissue damage is reduced compared to standard monopolar TURP surgery. The main advantage of bipolar TURP is increased patient safety allowing larger prostates to be resected without the usual time limitations and is just the latest in a long line of technological innovations in transurethral prostate resection.

No medical therapy or alternative procedure currently available can offer the same long-term overall improvement in urinary flow rates and symptom scores in essentially all patients with symptomatic BPH as TURP.