Obstructive Uropathy

OBSTRUCTIVE UROPATHY

INTRODUCTION:

Obstructive uropathy refers to the impairment of  renal function as a result of obstruction of the urinary tract.  Obstructive uropathy should be avoided as this is a reversible cause of kidney failure.

CAUSES OF OBSTRUCTIVE UROPATHY:

Obstructive uropathy can be due to obstruction of the urinary tract at any part but typically in the tubular part, namely, the ureter and the urethra. 

The causes of ureteric obstruction may include intraluminal causes, e.g. a stone or extraluminal causes e.g. enlarged lymph nodes or pelvic organs e.g. the uterus, cancer cervix.

The causes of bladder outlet obstruction could include enlarged prostate, urethral stricture or occasionally a urethral stone. 

Diagram urinary tract:

DIAGNOSIS:

Diagnosis of the obstructive uropathy would involve uro-radiology, namely, KUB, ultrasound, CT and CT scan. When intravenous contrast cannot be used, a MRI may occasionally be done without contrast to delineate the urinary tract better.  Ureterography, percutaneous or retrograde, can also be done.

TREATMENT:

The treatment of obstructive uropathy depends on the underlying cause. If the underlying cause is due to a stone, the stone will need to be removed as a matter of urgency. If it is due to an underlying malignancy, e.g. a lymphoma, cancer cervix, iatrogenic ureteric injuries, this has to be treated in an appropriate manner. 

The kidney can be drained, e.g. with a drainage tube. This may be an external drain, e.g. a percutaneous nephrostomy inserted under ultrasound and fluoroscopic guide.  if the patient is well enough to go to operating theatre, it may be possible to insert an indwelling ureteric stent. 

Written by:

Dr Clarence Lei Chang Moh, FRCS Urol, FEBU

Consultant Urologist

email: clarencelei@gmail.com

4 Sept 2013

Testicular Torsion

TESTICULAR TORSION

Any child or young man who presents with acute testicular pain is considered to have testicular torsion, until proven otherwise.  The etiological factor seems to be a congenital predisposition of the testis to a horizontal lie rather than the normal vertical lie.  The testis is twisted upon itself, giving rise to vascular strangulation. Depending on the degree of torsion, the torsion has to be relieved, usually within 6 hours to avoid testicular infarct. In real life practice, testicular torsion is often missed and often a subject of medico-legal negligence against the attending doctor and the surgeon.

Emergency surgery consists of scrotal exploration, untwisting the torsion and fixing the testicle with 3 sutures.  The fixation also has to be done for the contralateral testis.  However, if the testis is infarcted, the testis is best removed and consent has to be taken preoperatively for this as well.

However, only 50% of children and young men presenting with acute testicular pain are due to torsion.  The differential diagnosis is often that of inflammation e.g. epididymo-orchitis from viral infection especially mumps.  Urinary tract infection (in children with underlying UTI, urogenital tract abnormalities) and in young adults with other infections (e.g. TB, STD) can also present acutely with testicular pain.  However, upon taking a detailed history, they may be found to have an insidious onset, including constitutional symptoms e.g. fever, mumps in a close family member or in the school.

Emergency investigations can occasionally help to rule out torsion and this includes emergency Doppler ultrasound of the testis, epididymis and spermatic cord to trace the blood supply. In some medical centres, emergency isotope study can also confirm the vascularity of the testis.  When in doubt, it is always better to list the patient for emergency exploration.

Dr Clarence Lei Chang Moh, FRCS Urol

Consultant Urologist

email: clarencelei@gmail.com

10^th September 2013

Enclosures: Two sets of operative photographs indicating (a) testicular torsion infarcted and testicle removed, (b) testicular torsion twisted intraoperatively and salvaged.

Testicular Swellings

TESTICULAR SWELLINGs

INTRODUCTION:

A testicular swelling in a young adult is a cancer until proven otherwise.  Undescended testis (UDT) is a predisposing factor, even after orchidopexy.  Patients who have a history of undescended testis or testicular abnormalities e.g. atrophic testis from previous severe orchitis need to be taught TSE, testicular self examination to look out for the testicular masses.

The differential diagnoses of testicular swelling could include the following: Non-testicular swelling in the scrotum e.g. epididymal nodules, hydrocele and hernia. A hernia would usually extend into the inguinal region and is often reducible on lying down and there is a cough impulse.

INVESTIGATIONS:

To differentiate the swellings, investigations could include a scrotal ultrasound.  Urinalysis may help to point to infection as a cause of the epididymal or testicular swelling.  If a testicular swelling is confirmed, it is important to take blood for testicular tumour markers, namely, alpha fetoprotein, beta HCG and LDH. A chest x-ray can also be performed to see if there is any metastatic disease as the lung is a common site of metastasis from testicular cancer.

TREATMENT:

The initial treatment of testicular masses is surgical removal. It is important not to disturb the testicular swelling so as to prevent spread of the malignant cells.  It is considered a negligence to do an open biopsy of the testicular swelling through the scrotum as this will cause seedling of the malignant cells onto the scrotal skin.  The scrotal skin drains into the inguinal lymph nodes and the testicles drained into the paraaortic nodes.  Therefore, if the patient already has a scrotal testicular biopsy, subsequent radiotherapy will have to cove the inguinal lymph nodes as well as the paraaortic area!  The surgery is an inguinal incision so that the spermatic cord can be ligated early during the surgery and then testis is then mobilised up into the inguinal incision to be removed, a procedure known as inguinal radical orchidectomy.

Nowadays, testicular cancer is readily curable. The mainstay of treatment is the inguinal radical orchidectomy, followed by chemotherapy.  The type and dosage of chemotherapy depend on the extent of the disease. If the patient has a seminoma, they are also sensitive to radiotherapy as well.

Following surgery, the histopathology of the testicular tumour is important: either a teratoma or seminoma (the latter often referred to as non-teratoma).  The tumour marker should also be repeated, depending on the half-life of the tumour markers (few days to few weeks). It will be an indication that the patient has residual disease if the tumour markers remain elevated.  The tumour markers are also important to monitor during treatment. 

Testicular cancer spread to the regional lymph nodes, namely, paraaortic and subsequently to the mediastinum and chest. 

Fertility is often an issue in patients with testicular tumour.  Sperm banking has to be discussed with the patients pre surgery and chemotherapy, as the fertility is often markedly reduced, following treatment. 

Dr Clarence Lei Chang Moh, FRCS Urol

Consultant Urologist

email: clarencelei@gmail.com

10^th September 2013

Enclosures: Photographs of testicular mass preoperatively and testicular mass during radical inguinal orchidectomy.

Percutaneous nephrostomy

PERCUTANEOUS NEPHROSTOMY, Clinical Skills Lab

INTRODUCTION:

Percutaneous nephrostomy is an insertion of a tube into the pelvi-calyceal system to allow diversion of the urine output.  This can be  a life saving procedure when the urinary tract (usually the ureter) is obstructed with sepsis.  Putting a percutaneous nephrostomy would relieve the kidney failure as well as the underlying sepsis, both of which can be fatal. 

The common causes of ureteric obstruction include: obstruction by cancers e.g. cancer cervix, rectal cancers, metastatic disease to the retroperitoneal lymph nodes. 

Benign causes include ureteric strictures or fistulas, often iatrogenic, caused by the gynaecologists during surgery on the uterus.

Percutaneous nephrostomy is an expert procedure, usually done by the interventional radiologist or by the urologist. It is often done with the imaging by ultrasound and fluoroscopy. The pelvi-calyceal system should ideally be dilated to reduce the risk of injury to the kidney.  A suitably dilated calyx is punctured. This is usually the lower calyx to reduce the risk of injury to the pleura when the upper calyx is punctured.

Informed consent is important to get the patient’s cooperation and also to inform the family of the risk of the procedure including bleeding, injury to the nearby structures including the pleura and intestines.  The procedure is done after infiltration of the skin and tract with local anaesthesia. The dilated calyx is punctured with a percutaneous needle, usually an 18G puncture needle under ultrasound guide and tracking.  After the needle has entered the dilated calyx, urine is withdrawn and sent for bacterial culture.  A guide wire is introduced down the needle into the renal pelvis or  the upper ureter.  The tract is then dilated, usually 6 Fr, 8 Fr, 10 Fr serial dilators.  The percutaneous nephrostomy tube, usually 10 or 12 Fr is then inserted over the same guide wire into the pelvi-calyceal system to drain the urine. The percutaneous nephrostomy usually has a pigtail to reduce the risk of dislodgement from the pelvi-calyceal system.  The nephrostomy is also anchored with Silk sutures to the patient’s skin. The nephrostomy is then connected to a drainage urine bag.  Nephrostomy tubes can usually be left insitu for up to 6 months, although usually for much shorter. In the meantime, the underlying problems can be managed, e.g. radiotherapy for cancer of the cervix.

FOLLOW-UP:

If the urinary drainage is still required, the nephrostomy tube can be wired with a guide wire and if the guide wire can pass into the bladder, the nephrostomy tube can be changed to an indwelling ureteric stent. Again, this is done under fluoroscopy. 

Dr Clarence Lei Chang Moh, FRCS Urol

Consultant Urologist

email: clarencelei@gmail.com

10^th September 2013

illustrations in another document

Diet Stones

Renal Mass腎臟問題

Large solid vascular renal masses are usually cancerous. Such patients may present with  haematuria but many masses are picked up earlier at health screenings. There is however, no role for routine screening for renal masses except in those with such a strong family history or previous history. An incidental mass of the right kidney at the  lower pole, 5 x 4 cm is such an example. The standard practice nowadays is to have another imaging modality to confirm the ultrasound findings, especially any tumour thrombus in the renal vein and IVC.  The CT can also help to look for any para-aortic lymphadenopathy The commonest benign renal masses viz AML angiomyolipoma and oncytoma may exhibit characteristic lesions on CT. I will also do a chest x-ray at the same time.


One option is to do percutaneous ultrasound guided Trucut biopsies of the lesion.  However, the limitation of this is that  the  biopsy may not be representative of the tumour as renal cell carcinoma is heterogenous.  Biopsy can also cause bleeding and associated with the theoretical risk of biopsy tract seedling. One would also require a good uro-histopathologist to make a diagnosis. I would usually recommend a biopsy if we are thinking of systemic therapy without a nephrectomy, e.g. in the presence of metastatic disease.


One option is to remove the entire kidney with the tumour, for completeness of the surgery.


However, I would think the standard management would be a partial nephrectomy.  Partial nephrectomy is more complicated than total nephrectomy. It requires control of the renal vein, renal artery and probably
the insertion of ureteric catheter so that methylene blue can be  injected to detect any breach of the pelvi-calcyeal system which needs to be sutured. As the surgical margin  is renal tissue, there is also an increased risk of secondary haemorrhage, in addition to urinary fistula.  As with most surgeries, it can be done by three approaches: open, laparoscopic or robotic.  The later two usually takes longer.


“Minimally” invasive therapy includes cryoablation and radiofrequency. These ablative energies may be applied percutanously under ultrasound guide or laparoscopically. Tumour destruction is still incomplete. However, I would recommend such “MIT” only to patients who are unfit for surgery or who has
multiple bilateral lesions  where surgery is difficult.


The approach in small (<4cm) renal masses (SRM) is more conservative, which may include active surveillance in masses <3cm (incidence of primary metastatic disease 2.4 % compared to 8.4% if mass is 3-4cm)

Dr Clarence Lei Chang  Moh, FRCS Urol
clarencelei@gmail.com
20 Jan 2012

B P H , BENIGN PROSTATEHY PERPLASIA（良性前列腺增生症）

B P H ,  BENIGN  PROSTATEHY  PERPLASIA


BPH can cause obstructive urinary symptoms eg h e s i s t a n c y ,   p o o r   a n d  
i n t e r m i t t e n t   u r i n e   f l o w ,   t e r m i n a l   d r i b b l i n g   a n d   r e t e n t i o n .


Modern  practice would require that the urine flow be documented with a
uroflowmetry. A normal uroflowmetry is >15 ml/sec.  The post void residue
should also be <100 mls for most patients and any post void residue >300 mls
would be considered as having chronic retention with a risk of
hydronephrosis.

TWO types pf medicatons are used to treat BPH.
For patients whose prostate are proven to be enlarged (> 40 cc on rectal
exam or ultrasound per abdomen or transrectal TRUS), they will require a
medication  to reduce the size of the prostate gland.  This is done by
decreasing the dihydro-testosterone inside the prostate with  A v o d a r t
(Dutasteride) or Proscar (Finasteride) daily.  It takes 6 months to show any
clinical benefit.  He will have to take this on a long term basis, possibly for
many years, until a better agent comes along.   This agents cost about RM7
per day.

To improve his uroflow quickly (days) , one can use an alpha-blocker to relax
the adrenergic nerves to the prostatic urethra. The available ones include
Harnal (Tamsulosin),  X a t r a l (Alfuzosin), Hytrin (Terazosin), Cardura
(Doxazosin). The side effects  are those of postural hypotension and
ejaculatory disturbance.  The cost range from RM1 to RM4 per day.

Other symptoms may not due to the prostate but from an overactive bladder,
OAB.  These symptoms include f r e q u e n c y ,   n o c t u r i a ,   a n d   u r g e n c y. In
such cases, an anti-cholinergic would be more useful e.g. Detrusitol
(Tolterodine or V e s i c a r e (Solifenacin).
If there is pain,one should exclude an UTI or stones.


If there is gross hematuria one need to exclude a bladder or renal tumour.
Bladder outlet obstruction and overactive bladder may be associated with
erectile dysfunction, ED.  Many of these patients would also benefit from
PDE-5 inhibitor (phosphodiiesterases type 5) e.g. Sildenafil (Viagra),
Vardenafil (Levitra) or Tadalafil (Cialis).  Sildenafil is now available as a
generic from Ranbaxy at just over RM10/- per table when the original Viagra
is about RM45/-.  US FDA also recent approved d a i l y   d o s e   o f   T a d a l a f i l
5 mg to be used for both erectile dysfunction and bladder outlet obstruction.

A further factor to improve patients with lower urinary tract symptoms is the
possibility of adding on testosterone hormonal replacement. A clue to such a
disorder (TDS, Testosterone Deficiency Syndrome) is that the patient has
other aspects of the metabolic syndrome e.g. obesity, hypertension, diabetesas well as  loss of libido, erectile dysfunction, general tiredness. The biochemical diagnosis of TDS is finding a total testosterone of <11 nmol/ml. They can now be very effectively treated by intramuscular injection of
N e b i d o  1 gm every 3 months.

Thank you very much for your attention.

Dr Clarence Lei Chang Moh
Consultant Urologist
e-mail: clarencelei@gmail.com  
13 January 2012

Ref:

Benign prostatic hyperplasia
(Diagram taken from http://en.wikipedia.org/wiki/Benign_prostatic_hyperplasia

Diagram illustrating normal prostate (left) and benign prostatic hyperplasia (right).