LECTURE: Bladder Outflow Obstruction – Thursday, July 30, 2020

The details for the call-in Zoom Meeting lecture is ONLY good for Thursday July 30, 2020.

Transurethral Vaporization of Prostate and Cystometrogram

INTRODUCTION

The disease burden of Benign Prostatic Hyperplasia (BPH) is in the increase because there is a greater awareness and increase in life expectancy. The fact that effective medical treatment is available and also the presence of minimally invasive procedures has contributed to more people seeking treatment.

BENIGN PROSTATIC HYPERPLASIA

BPH is the most common cause of urinary obstruction in men. Histological evidence of the disease is present in over 50% men over 50 years and in 90% of men above 90 years.

SYMPTOMS OF BPH

The symptoms of BPH are collectively known as LUTS (Lower Urinary Tract Symptoms). They are divided into Obstructive and Irritative symptoms.

 The Obstructive symptoms are as follows:

• Hesitancy
•  Weak stream
•  Straining to pass urine
•  Prolonged micturition
•  Feeling of incomplete emptying
•  Urinary retention

The Irritative symptoms are:

• Frequency
• Nocturia
•  Urgency
•  Urge incontinence

The other symptoms include Haematuria, recurrent Urinary tract infections and renal insufficiency. Haematuria might be gross or microscopic and is a serious symptom and needs prompt investigation.

PATHOPHYSIOLOGY OF BPH

Anatomical or mechanical obstruction accounts for about 60% of the obstruction due to BPH. The alpha one mediated contractions are responsible for the dynamic obstruction {40%}.

DIAGNOSIS

For clinical evaluation history and digital examination is important. Following which the investigations that are recommended include:

• Urinalysis
  • Renal Function
  • PSA
  • USG (Residual Urine)
  • Uroflowmetry

PSA or Prostate specific antigen is one of the most important tests as it is -

• Most widely used tumour marker.
• Revolutionized the diagnosis & Management of carcinoma prostate
• PSA is prostate-specific, not cancer specific.

The normal values are as follows (0 – 4    Normal, 4 – 10   Borderline, > 10     Significant)

CMG – CYSTOSCOPY

About one third of the nerves of the spinal cord are involved in control of the bladder functions. God has created our urinary bladder in such a wonderful way that the bladder can accommodate increasing volumes of urine without increasing the pressures inside. Even when full there are several levels of control mechanisms. When someone wants to pass urine, he or she has to decide how long it will take to reach a convenient place and make sure the place is not occupied. He or she has to undress and start voiding only when everything is comfortable. While voiding the valve mechanism should relax and the muscles should contract and totally empty the contents of the bladder.

A variety of diseases and just old age can affect the various control mechanisms. Most commonly minor disturbances in the neurological status could present with symptoms. Just getting older or having diabetes could affect the nerves. Prostate gland and strictures can cause blocks. Stones and anatomical disturbances could again present with symptoms.

SYMPTOMS OF URINARY DISEASE

The following are the common symptoms of urinary tract disease and the Urodynamic studies (CMG – Cystoscopy) would help to find out the cause of the disease.

1. Increased frequency of urination and nocturia:  this common symptom could be due to a variety of causes. Tuberculosis and neurological disease could decrease the size of the bladder. Inflammation and thickening of the wall of the bladder will make it lose its elasticity and this leads to higher pressures at lower volume and wanting to pass urine. If there is significant amount of residual urine after voiding the functional capacity of the bladder is reduced. Unstable contractions or contractions of the bladder when the valve is not open can lead to increased desire of voiding.
2. Hesitancy, poor stream and dribbling: These are symptoms of obstruction. When there is a block in the urinary passage the bladder has to generate more pressure to overcome the block whether it is due to enlargement of the prostate gland or to narrowing of the urethra. Once the block increases further the urinary stream become poor and there could be some dribbling towards the end of voiding
3. Sensation of incomplete voiding: When there is a block and the muscles need to work hard or if there is problem with the nerves or muscles the voiding will not be complete. This is felt as sensation of incomplete voiding. Sometimes the valve that prevents urine from going up into the kidney might be damaged and after voiding the urine that went up would come down giving the sensation of incomplete voiding.
4. Dysuria and lower abdominal pain: this sensation of burning while passing urine is commonly due to irritation caused by infection or otherwise.
5. Incontinence [including urge and stress incontinence]: Prolonged obstruction can cause uninhibited contractions, and this presents as extreme urgency and leak of urine before getting the toilet. Neurological dysfunction can present similarly while stress incontinence which is due to laxity of the pelvic floor muscles present as urgency when the bladder is full.

The procedure:

The following are made available before starting the procedure

1. Tape measure in centimeters
2. IV stand
3. Two infant feeding tubes [8 and 5 F sizes]
4. Two IV tubing
5. 2 Normal saline bottles
6. 2% Xylocaine jelly tube
7. Set for cleaning and draping

An antibiotic injection is given about half an hour prior to the procedure. First the patient is asked to void and empty the bladder. After cleaning and draping the IV stand is placed near the pelvis of the patient such that the ‘0’ reading of the tape measure is at the level of the pubic symphysis and the rest is upwards. Both the infant feeding tubes are passed together lubricated with lots of sterile jelly into the bladder. The IV sets are connected as follows:

• The 8 F tube to the normal saline bottle
• The 5 F tube to the locally made manometer with the IV tubing. The IV tubing is placed along the tape measure and held with adhesives. The patient is requested to cough to make sure that the saline or urine in the tubing moves and the upper level is visible and noted.

The resting pressure in cm of water is noted and recorded. The bladder is then slowly filled through the 8F feeding tube. The volume of saline that has gone in and pressures are recorded and continuously monitored looking for the following:

1. The sensations: the sensation of urine in the bladder, the sensation of desire to pass urine, the sensation of urgency and pain or any other sensations.
2. The presence of unstable or uninhibited contractions. With these the bladder pressures slowly rise and come down during the filling phase unlike the rise in pressure that occurs due to increase in intra-abdominal pressure [in which the pressure goes up and comes down quickly]. The act which increases the intra-abdominal pressure like coughing etc. could be observed.
3. The patient is requested to void when he/she cannot hold anymore urine. If possible, it should be carried out in the supine position in the table. However, if unable to do so the patient could be made to stand up making sure that the tubes are intact and the zero in the tape still corresponds to the level of the pubic symphysis. Sometimes it might be necessary to remove the 8F filling tube and request most of the staff especially those of the opposite sex to leave the room and observe the reading when the patient is not looking at you. The pattern of voiding or the voiding curve and the maximum voiding pressure is noted.
4. Once voiding is completed the residual volume is measured by emptying the bladder with the tubes and the volume is recorded.

SOME INTERPRETATIONS

• Normal findings: Usually the maximum voiding pressure is about 40 cm of water in women and 60 cm of water in men. Unstable contractions are not present. The first sensations occur about 150 ml of volume and normal desire to void at 350 ml. The resting pressure in the bladder is about 10 to 15 cm of water and till the volume reaches about 350 ml there is no significant increase in the pressure. This is because the bladder does not behave like a balloon and God has created the muscles fiber arrangement such that this elasticity is there.
• In conditions like diabetes the sensory nerves are affected so that the person does not feel anything even if the bladder is filled to 1000 ml. Impaired sensations occur with Neurovesical dysfunction due to a variety of causes. Sensations like pain, burning, urgency, etc. could occur with Neurovesical dysfunction.
• The compliance of the bladder wall is poor when there is thickening of the wall which can occur with Neurovesical dysfunction, long standing obstruction, with infection and infiltrations that can include diseases like tuberculosis. Here the bladder is not elastic anymore and the pressure rise with increasing volumes and later the capacity of the bladder is less.
• Unstable contractions could be due to Neurovesical dysfunction or long-standing obstruction. Sometimes leak of urine is associated with these contractions and rarely patients cannot hold more than 100 ml of urine in the bladder due to unstable contractions
• With obstruction the maximum voiding pressures start rising and because of this there is hesitancy, or it takes longer time for the urine to come out. Higher pressure contractions cannot be sustained for a long time and there in intermittency because the flow is augmented by abdominal contractions. Finally, there is incomplete voiding and significant post void residual urine. When the maximum voiding pressure exceeds 90 cm of water, we generally recommend surgical treatment especially TVP as the morbidity is significantly low and the chances of acute painful retention are much higher with MVP of > 100 cm of water. Medical treatment could be tried for pressures between 60 to 90 cm of water.
• With bladder stones sometimes there is sudden stoppage of passing urine

Cystoscopy can reveal the following:

• Stenosis or narrowing of the meatus or the opening
• Strictures or narrowing in the urethra
• Stones in the urethra or bladder
• Tumours in the bladder
• Enlargement of the prostate
• Hypertrophied muscles or trabeculations in the bladder that occurs with Neurovesical dysfunction.

TREATMENT

The options that are available are

• Watchful Waiting

• Medical Rx        :   α 1 blockers                  

            5αReductase inhibitors

• Surgical Rx       :    TURP / TUIP

            Open Prostatectomy

• Minimally invasive procedures              

The objectives of medical treatment are improvement of symptoms and prevention of disease progression. The risk factors for progression are as follows

• Advanced age (> 62 years)
• Prostate size ( > 30 cc )
• PSA ( > 1.6 ng/dl )
• Severe symptoms
• Post-void Residual Volume ( >39cc )

The medical treatment consists of the following

A: Alpha-1 Receptor Blockers (PRAZOSIN, DOXAZOSIN and TERAZOSIN)

• Since alpha-1 receptors are also present in the CVS, side effects like orthostatic hypotension occurs.
• URO SELECTIVE: (Alpha 1A) [Tamsulosin (Dynapres 0.4mg), Alfuzosin    (Alfoo 10mg)]

Tamsulosis or Urimax is the first prostate specific alpha 1 receptor blocker and does not need dose titration and can be given with other antihypertensives. It is given at 0.4 mg daily and unlike Alfuzocin can cause retrograde ejaculation.

5 alpha reductase inhibitors (Finasteride, and Dutasteride) prevent conversion of Testosterone to Dihydro Testosterone.  While Finasteride inhibits type 2 receptors Dutasteride inhibits both type 1 and 2 receptors.

A Combination of A-1a blocker & 5-AR Inhibitor (e.g. Tamsulosin & Dutasteride) significantly reduces clinical progression of BPH, risk of AUR & need for surgery.

It is important that Carcinoma of the prostate must be carefully excluded before medical treatment for BPH.

The contraindications to medical treatment are as follows:

1. Acute Urinary Retention
2. Palpable Bladder, large post-void residual urine
3. Renal Insufficiency due to BPH
4. Recurrent UTI
5. Recurrent hematuria
6. Bladder Stones or large diverticula                                       

Transurethral resection of prostate or TURP is the gold standard for surgical treatment. It has less than 02% mortality and low morbidity.

Open prostatectomy is reserved for the following conditions

• Large glands
• Ankylosis of hip preventing proper position of the patient
• Co-existent conditions requiring open surgery   e.g. Diverticula, Large calculus
• Severe urethral strictures

There are minimally invasive procedures like transurethral incision of prostate for very small glands and laser therapy. The newer modalities include:

• Transurethral Needle Ablation of the prostate (TUNA)
• Transurethral Microwave Thermotherapy (TUMT)
• Prostatic stents
• Transurethral vapourisation of prostate (TUVP)

TRANSURETHRAL ELECTRO- VAPORIZATION OF PROSTATE [TVP]

Electrovaporization of the prostate is a safe, effective and economic alternative to standard transurethral electroresection of the prostate (TURP). Electrocautery machines at 400W for cutting current and 300W for coagulation current were used for the procedure. Glycine (1.5%) was used for irrigation. A 27-Fr resectoscope manufactured by Karl Storz with the roller type Vaportrode (Karl Storz, Tuttlingen, Germany) was used for the procedure, which is similar to transurethral resection of the prostate except that prostatic or tumour tissues could be vaporized both during to and from movements of the probe.

The procedure is carried out as follows:

After cleaning and draping and placing in Lithotomy position the electro - cautery machine is set to 400 watts of cutting current. The resectoscope with the obturator is introduced first. Once inside the bladder the obturator is removed and working element is connected. The camera should be held by the left hand which should be fixed to show the 12 o’clock position always. The working element could be rotated and indicates the correct location. The prostate gland is inspected with special reference to the verumontanum. A little bit of the tissue could be vaporized near [distal to the] veru to mark the limit of vaporization.

The vaporization is started at the median lobe and initially both sides to form a passage for free flowing of irrigation fluid. The lateral lobes are then vaporized slowly till the shining white capsule is reached. The prostatic tissue has a brownish granular appearance while the capsule could be easily appreciated. If there is lots of air bubbles the scope could be tilted sideways or shaken to get the bubbles off.

If necessary few chips could be resected for biopsy. Once the surgery is finished careful hemostasis is achieved and 3-way foley’s catheter is placed. Foley’s catheter introducer might be necessary sometimes. The volume of the fluid injected to the Foley’s balloon in ml roughly equals the volume of prostate resected or vaporized [in grams]. The irrigation fluid should be available for connecting as soon as the catheter is placed. The balloon is inflated with saline or distilled water and the amount used is roughly equal to the size of the prostate vaporized. The irrigation is continued for about 24 hours and stopped if it is clear. Attempts should be made to make sure that there is no air lock [bubbles] inside the tubing.

 The advantages of the procedure are that there is hardly any bleeding, no dilution hyponatraemia and the patient acceptance is good. The disadvantages are that there is no tissue for biopsy and the need for repeat procedures are higher because of incomplete removal and stricture formation.

Recently we have used normal saline for carrying out the vaporization procedures as these are much safer and have minimal complications.