Infra vesical obstruction

1. Infra-vesical obstruction
How and when
By
Mohamed Shafik Shoukry, M.D.

4. Obstruction
• Infra-vesical obstruction
• Outflow obstruction
• Bladder outlet obstruction
•Obstruction somewhere
in the outflow tract

5. Assessment of Infra-Vesical
Obstruction
• Easy to diagnose and treat when the cause is a
urethral stricture, stone (bladder or urethra)
• May be Difficult to assess when the cause is
enlarged prostate with LUTS.
• To exclude weak Detrusor when suspected.
• LUTS is vague term. Irritative symptoms may
be difficult to treat.

6. Basic Assessment
• Symptoms: mainly obstructive.
• DRE is a must
• U/S Abdomen and Pelvis: bladder capacity,
Prostate size, stones, PVR.
• Lab.: Routine including PSA.

7. Morbidity of Urodynamic studies
Non obst. Obst. Authors
Mild dysurea
bacteriuria
♂
♀
Micro. Haemet.
Retention
33-57%
4-6%
3-4%
6%
-
76%
10-14%
7-8%
6%
5%
Bombieri
99
Porru 99
Klinger 98
Linger 98
Gonnerman 96  morbidity (7 Fr. D.L. Cath.)

8. Obst. + normal
det.
Obst +week
det.
Non obst. +
det. normal
Non obst.
weak det.
Gotoh Lt 99 95% 80% 52% 52%
Favle P 98 100% 53% 35% 0%
Prognostic value of unodynamics

9. P/Q
* Clear association between classical obst
and better outcome
* Boo --> indication of surgery
Det. contractility --> Prognostic of
surgical outcome.

10. When to Worry??
• Irritative Symptoms
• Imaging: Ultrasound: Huge bl. capacity
• PVR: > ???
• Neurogenic suspission!!
• Disc, D.M. , Parkinson, and many others….

11. When to do UDS
•Pressure-Flow Study
To do or not to do…..
this is the question

12. AUA Guidelines
• 16. Clinicians may perform multi-channel
filling cystometry when it is important to
determine if DO or other abnormalities of
bladder filling/urine storage are present in
patients with LUTS, particularly when invasive,
potentially morbid or irreversible treatments
are considered. (Expert Opinion)

13. AUA Guidelines
• 17. The literature is inconclusive
and "pure" symptomatalogy is
rare; therefore, this guideline
will not specify whether UDS
testing should be done
routinely in SUI or LUTS.

14. AUA Guidelines
• Clinicians should perform PFS in men when it
is important to determine if
urodynamic obstruction is present in men
with LUTS, particularly when invasive,
potentially morbid or irreversible treatments
are considered. (Standard: Evidence
Strength: Grade B)

15. AUA Guidelines
• In more complicated/complex individuals with
LUTS, there may be a role for various types of
UDS testing in order to exclude complicating
factors and potentially guiding therapy.
• In clinical practice, the role of invasive UDS
testing is not clearly defined. Urologists generally
accept that conservative or empiric, non-invasive
treatments may be instituted without
urodynamic testing.

16. EAU Guidelines
• A large PVR is not a contraindication to
watchful waiting (WW) or medical therapy,
although a large PVR may indicate a poor
response to treatment and especially to WW.
In both the MTOPS and ALTESS studies, a high
baseline PVR was associated with an increased
risk of symptom progression

17. EAU Guidelines
• There are no published RCTs in men with LUTS
and possible BPO that compare the standard
practice investigation (uroflowmetry and PVR
measurement) with PFS with respect to the
outcome of treatment but one such study is
ongoing in the UK.
• Patients with neurological disease, including
those with previous radical pelvic surgery should
be assessed according to the EAU Guidelines on
Neuro-Urology

18. EAU Guidelines
• Due to the invasive nature of the test, a
urodynamic investigation is generally only
offered if conservative treatment has failed.
The Guidelines Panel attempted to identify
specific indications for PFS based on age,
findings from the other diagnostic tests, and
previous treatments. The Panel allocated a
different degree of obligation for PFS

19. EAU Guidelines
• in men > 80 years and men < 50 years, which
may reflect the lack of evidence. In addition,
there was no consensus whether PFS should
or may be performed when considering
surgery in men with bothersome
predominantly voiding LUTS and Qmax > 10
mL/s, although the Panel recognised that with
a Qmax < 10 mL/s, BOO is likely and PFS is not
necessarily needed.

20. Recommendations
•
• PFS should be performed only in individual patients
for specific indications prior to invasive treatment
or when evaluation of the underlying
pathophysiology of LUTS is warranted. 3 B
• PFS should be performed in men who have had
previous unsuccessful (invasive) treatment for
LUTS. 3 B
• When considering invasive treatment, PFS may be
used for patients who cannot void > 150 mL. 3 C

21. Recommendations
• When considering invasive therapy in men with
bothersome, predominantly voiding LUTS, PFS may
be performed in men with a PVR > 300 mL. 3 C
• When considering invasive treatment in men with
bothersome, predominantly voiding LUTS, PFS may
be performed in men aged > 80 years. 3 C
• When considering invasive treatment in men with
bothersome, predominantly voiding LUTS, PFS should
be performed in men aged < 50 years. 3 B

22. PFS Pitfalls
• it is necessary to measure the
bladder pressure via a
transurethral (or suprapubic)
catheter.

23. Pressure-Flow Study
• This invasive procedure includes some risk of
UTI, urethral injury and may be painful to
some patients.
• It is the golden standard to evaluate bladder
pressure, so far.
• During PFS, bladder pressure and flow rate are
measured simultaneously.

24. • A high bladder pressure and low flow rate
indicates that the patient has obstruction
somewhere in the outflow tract.
• A low bladder pressure and low flow rate
indicates that the patient has a weakly
contractile bladder muscle, possibly combined
with obstruction.

25. Non-Invasive Evaluation of
Vesical Pressure
A new concept in
Urodynamics

26. Isovolumetric Bladder Pressure
• The highest Vesical pressure
recorded when sessation of urine
flow occurs during micturition.
• This pressure can be measured
using stop Flow test.

27. Stop Flow Test
• The isovolumetric bladder pressure is
measured by either:
– voluntary interruption of flow rate,
– by pulling a balloon into the bladder neck during
voiding
– or by mechanical compression of the penile
urethra.
• Could it be also measured non-invasively?

28. Stop-flow pressure

29. Stop-Flow Vesical Pressure
• 6-Fr Urodynamic Catheter is inserted
• Pressure-Flow study is done
• During voiding phase, mechanical occlusion of
the penile urethra till flow completely stop
• Mark the highest Pves as “Stop-flow pressure”
• This pressure indicates the highest potential
pressure developed by the detrusor muscle.
• Patients were asked to avoid straining, were
monitored by rectal balloon for Pabd pressure
assessment.

30. Concept of non-invasive estimation of
Pves
• If the patient is voiding into a confined device
until flow stops, the pressures within the
device, the urethra and the bladder are
equalized.
• non-invasive estimation of vesical pressure is
possible by measuring the pressure within
that device.

31. Isovolumetric Vesical Pressure

32. • Limiting factors will be:
– voided volume
–Distensibility of the device
–Leakage and spills of urine

33. Non Invasive Pves Evaluation
• Never recorded in the literature, many trials!!
• New concept to allow evaluation of the Pves
without insertion of urethral catheter
• The patient will void into the least distensible
commercially available condom catheter.
• The patient will start voiding into the condom
which is connected to the pressure transducer
of Urodynamic machine at the same level as
the symphesis pubis.

34. Non Invasive Pves evaluation
• The flow stops when near maximum distensibility
of the condom is reached. The volume of urine
would range between 100-200 c.c. (mid void
volume)
• The highest recorded pressure occurs when the
device is full of urine and the flow almost stops.
• Leakage from the condom-from both ends- is the
major problem and is guarded from closely.
• The trial is repeated twice and the mean
“Transmitted Isovolumetric Pves” is recorded

35. Pitfalls and Technical Problems
• No rectal catheter was inserted to keep the
test completely non-invasive.
• Patients were instructed not to strain during
voiding and were closely monitored for
straining.
• Any straining resulted in exclusion of the
results of that test.
• Non-invasive test should be done in non
straining patients only.

36. Protocol of Research
• Patients will undergo Pressure flow study
• Evaluation of “Stop-flow pressure”.
• This is followed by a non-invasive urodynamic
test for evaluation of “Transmitted Stop flow
pressure”
• Statistical comparison of both pressures will
done.
• Study of feasibility, efficiency and cost-
effectivity will be carried out.

37. Poster presented in AUA 2014

38. Pilot study results
• Pilot study was performed on 20 patients in
2014.
• Mean stop-flow recorded was 69.5 cm/H2O
(+/_ 43 )
• Mean estimated non-invasive pves was 60 cm/
H20 (+/_37 )
• No significant difference was found between
both pressures (p<0.005)

39. “Estimated non-invasive Pves”
• Estimated non-invasive Pves is compared to
that of Stop-flow pressure.
• The study was done on non obstructed
patients undergoing urodynamic study for
other urologic problems, like Nocturnal
Eneuresis
• Then we are starting measuring it in patients
with BPH.

40. Conclusion
• Non-invasive assessment of infra-
vesical obstruction could be done
by identification of Vesical
pressure in a condom catheter
attached to pressure transducer
of U/D machine in association
with a simple uroflowmetry.

41. Detrusor muscle reserve that compensates for
increased infravesical resistance is not well studied.
In the literature, still no valid objective test is
available to estimate the power reserve of detrusor
muscle and its ability to overcome the increasing
resistance to urine flow.
DETRUSOR MUSCLE RESERVE

42. A of DMR is proposed. It depends on
adequate bladder emptying within normal flow range.

43. A is proposed to evaluate DMR by a non
invasive technique.
This study evaluates this new test in adult males

45. no urological complains
no obstructive symptoms
no clinical or radiological
evidence of urinary
obstruction.

46. Any clinical or radiological
evidence of infravesical
obstruction
Qmax < 15ml /sec.

47. The subjects were asked to void through a
condom catheter into a vertical glass tube
of variable heights placed at the level of
symphesis pubis. The covered glass tube
guides the urine to a uroflowmeter
Our special test was designed to evaluate
the detrusor muscle reserve.
The test aims at the estimation of change
in Qmax using graduated tubes carrying
urine into increasing heights from the
symphysis pubis to simulate outflow
resistance.

48. A single uroflow was measured per day to avoid bladder and
patient exhaustion.
A series of glass tubes of variable heights (10, 20,30,40,50
and 60cm) with fixed internal caliber of 14 Fr. were used

49. 10 cm 20 cm 30 cm 40 cm 50 cm 60 cm
Condom

51. Mean Qmax of each test was compared to the subject’s
initial mean Qmax. PVR was measured after each test
using trans abdominal ultrasound
A cut-off level of in each group passing
the test (Qmax > 15ml/sec and PVR <50 ml)
was designated as the normal level of outflow resistance
passed by that age group of males
70% of subjects
70% of subjects
the normal level

52. Overall, Qmax
decreased with each
increase of height
resistance
0
5
10
15
20
25
30
0 10 20 30 40 50 60
Mean
of
Peak
flow
rate
(mL/sec)
Height Resistance (cm)
25.3
16.2

53. 0
5
10
15
20
25
30
Zero 10 20 30 40 50 60
Mean
of
Peak
flow
rate
(mL/sec)
Height resistance (cm)
<40 yrs
40 – 60 yrs

54. Mean maximum flow rate (Qmax) decreased progressively with
each increase in height resistance.
Severe decrease with the 10cm height resistance tube. (17.9% in
group I and 11.3% in group II).
Milder decrease in Qmax in next three height resistance tubes
(0.9% - 7.5%)

55. A total decrease of mean Qmax
at 60cm height resistance
reached 32.2%in group I and
40.3% in group II ( p=0.128)
Height
resistance (cm)
Qmax
Change
Qmax
Change
P.
Value
<40yrs
ml/sec (%)
40 – 60yrs
ml/sec (%)
Zero- 10 cm 4.8 (17.9%) 2.7(11.3%) 0.069
Zero – 20 cm 5(18.7%) 3.9(16.3%) 0.365
Zero -30 cm 6.1(22.8%) 5.4(22.6%) 0.98
Zero – 40 cm 6.5(24.3%) 5.7(23.9%) 0.874
Zero – 50 cm 8.4(31.5%) 7.3 (30.6%) 0.699
Zero - 60 cm 8.6(32.2%) 9.6 (40.3%) 0.128

57. Mean Qmax remained ≥15 ml/sec in all males in group I
except for only two adults up to the height resistance of
50cm. At 60cm height resistance, a total of five males
(16.5%) had mean Qmax<15 ml/sec.
In group II, significantly more subjects had mean
Qmax<15 ml/sec. At 30cm height, 24% had mean Qmax
<15ml/sec. At 60cm height resistance, 15 subjects (50%) had
Qmax<15 ml/sec (P=0.012)

58. 0 30 (100.0%) 30 (100.0%) 1.00
10 29 (96.7%) 28 (93.3%) 0.751
20 29 (96.7%) 25 (83.3%) 0.107
30 30 (100.0%) 23 (76.7%) 0.036*
40 30 (100.0%) 24 (80.0%) 0.048*
50 28 (93.3%) 22 (73.3%) 0.077
60 25 (83.3%) 15 (50.0%) 0.012*

59. 0 0 100.0%
10 3 95%
20 6 90%
30 7 88%
40 6 90%
50 9 85%
60 20 66%

60. Overall, mean PVR
remained below
50ml till
40cm height
resistance for whole
60 subjects
0
10
20
30
40
50
60
70
80
90
0 10 20 30 40 50 60
Mean
of
PVR
(mL)
Height Resistance (cm)

61. 0
20
40
60
80
100
120
Zero 10 20 30 40 50 60
Mean
of
PVR
(mL)
Height Resistance (cm)
<40 yrs
40 – 60 yrs

62. Mean PVR in group I remained<50ml for all males except
one till 30cm height resistance.
PVR progressively increased with increase in height
resistance.
At 50cm height resistance only 56.7% of subjects had
PVR<50ml.
In group II, mean PVR progressively increased even
faster. At 30cm height resistance only 60% of subjects had
PVR<50ml.

63. 40 cm H/R for males <40years and 20cm H/R for
males 40-60 years old is designated to be the normal
level
0 30(100.0%) 30 (100.0%) 1.00
10 30(100.0%) 25 (83.3%) 0.098
20 29 (96.7%) 22 (73.3%) 0.071
30 29(96.7%) 18(60%) 0.036*
40 23 (76.7%) 10(33.3%) 0.001*
50 17 (56.7%) 4(13.3%) 0.001*
60 14 (46.6%) 3(10%) 0.001*

64.  With applying height resistance, there was a change of
Curve shape.
 The change was in the form of one of two shapes.
 either in the form of interruption of stream or in the
form of obstructed plateau shape.

71. Detrusor Muscle Reserve is defined as the capability of
detrusor muscle to maintain flow and bladder emptying
within normal range, in spite of increase in outflow
resistance

72. DMR is a promissing new tool in the Armamentarium of
urologists for the early detection of weak detrusor before
prolonged infravesical obstruction leads to irreversible
damage

73.  A new test for estimation of DMR was designed
 The test is simple, safe, feasible and without
complications.
 The technical difficulties faced were minimal, mainly
avoiding straining.

74.  The test has the advantage of being non invasive
urodynamic test.
 It allows a sequential evaluation of detrusor reserve
when facing progressive outflow resistance.

75.  40 cm height resistance for adult males <40years and
20cm height resistance for males 40-60 years old is
designated to be the level to which such males should
be tested against to estimate their detrusor muscle
resistance