Table 15. Characteristics of studies comparing vas occlusion techniques with and without fascial interposition
Authors
Type of Study
and Year of
Publication
Schmidt 1973
[20]
Case series with
historical
controls
Subject’s Eligibility Criteria
Sample Size*
Setting
Study Period
Interventions
Isolation
Method
Unspecified
No FI: 150
Office,
FI: 135
USA
Between 1955 and 1961
Two lateral
openings
Occlusion
Type and Number
of Surgeons
Method
No FI: Double ligation with One urologist
cotton each end + Excision
(10 mm)
FI: Same + FI with suture
(prostatic end)
Rhodes et al.
1980 [46]
Li et al.
1994 [32]
Case series with
historical
controls
Unspecified
Non-randomized
trial. Subjects
divided in 7
groups (A to G)
Healthy volunteers who had had more
than 2 children
No FI: 28
Unspecified,
FI: 12
USA
No FI: 186/215
(Group G)
Five family
planning services,
FI:183/200 (Group
A)
China
Unspecified
Vasectomies done April
1988 through March 1990
plus two-year follow-up
Two lateral
openings
No FI: Vas transected
NSV
No FI (G): Open-end
1994-2003
Case series with
historical
controls
All vasectomies performed between
1971 and 1991
(Group B)
FI: 380/431 (Group
C)
In all groups, excision (1015 mm)
No FI: 550
FI: 4,015
Profamilia Male
Clinic in Medellin
Colombia
Vasectomies done between
1971 and 1991
2003 [45]
Randomized
clinical trial
Healthy, sexually active men at least
18 years old who had chosen
vasectomy for contraception
No FI: 422
FI: 419
Total initially
planned: 1,200
*Number of subjects analysed/total number of subjects enrolled in the study.
FI: fascial interposition, NSV: no-scalpel vasectomy.
8 research centers
worldwide: USA,
Mexico (2 sites), El
Salvador, Panama,
Sri Lanka, Nepal
No FI: Two
lateral openings
FI: Two lateral
openings,
sutured only if
bleeding (41%)
and NSV (59%)
[25,26]
Sokal et al.
FI: Same + FI with suture
(end?)
Various experienced
(>2,000 vasectomies)
FI (A) Open-end + FI (end?) operators. Each
technique done by
No FI (B): Ligation with
operators from 2
silk on both ends
different institutions
FI (C): Same as B + FI
(testicular end)
No FI: 427/488
De Los Rios
et al.
Unspecified
Recruitment from
November 1999 to May
2001 Recruitment halted
after interim analyses
showing superiority of FI
NSV
No FI: Ligation with
various suture materials +
Excision (10 mm)
At least two urologists
(in a teaching center)
FI: Same + FI
No FI : Ligation with silk +
Excision (10mm)
FI : Same + FI (testicular
end)
Various surgeons who
attended a
standardization
meeting
Table 16. Outcome measures of studies comparing vas occlusion techniques with and without fascial interposition
Authors and
Year of
Publication
Schmidt
Effectiveness
Data
Collection
Method of
Follow-up
Main Outcome Measures
No number, motility nor
Retrospective
time specified. Sterility with
2 negative specimens, 1
month apart
Unspecified but
variable
Unspecified
Granuloma: leakage of sperm from the
proximal vas
Retrospective
Unspecified but
variable
Unspecified
No number, motility nor
time specified but SA
results in failure described
N/A
N/A
N/A
Prospective
2 years
6 months intervals until 2
years post vasectomy
Presence of sperm two years Prospective
after vasectomy
2 years
Follow-up visits
every 6 months
Bleeding, infection, stasis
Retrospective
At least 3
months but
variable
3 months or after 20
ejaculations
Presence of live
spermatozoa four months
after vasectomy
Unspecified
Early postvasectomy
follow-up visit
and spontaneous
medical
consultations
Infection, bleeding, pain, granuloma,
orchi-epididymitis, sexual dysfunction
Prospective
12 months
2 weeks, then every 4 weeks Early: > 5 million motile
Prospective
through 34 weeks or until
sperm/mL at 14 weeks or
success or failure, and 52
later
weeks
Late: motile sperm at > 26
weeks or later (>10% motile
and >100,000 sperm/mL)
12 months
Follow-up visits
at the time of SA
Surgical difficulties and adverse events:
pain, sperm granuloma, orchiepididymitis, hematoma, infection
1994-2003 [25,26]
Sokal et al.
Definition of Failure
Length of
Follow-up
Unspecified
1994 [32]
De Los Rios et al.
Timing of SA
Data Collection
Unspecified but
variable
1980 [46]
Li et al.
Post-vasectomy Semen Analysis (SA)
Retrospective
1973 [20]
Rhodes et al.
Length of
Follow-up
Complications
2003 [45]
N/A: not applicable, SA: semen analysis.
N/A
Retrospective
No
No
?
Yes
?
No
?
Rhodes et
al. 1980
3
40
0.08
?
No
?
?
No
±
Yes
No
No
?
Yes
?
No
97.5%
2
807/
369†
0.70/
No
Yes
No
No
Yes
Yes
Yes
Yes
Yes
?
Yes
Yes
Yes
88%/89%†
No
No
Yes
?
Global Assessment
?
Adequate
Assessment*
Yes
Sample Size
No
Follow-up
Yes
Provider
?
Setting
No
Study Period
?
Participants
0.32
Power*
285
Follow-up Rate*
Systematically
Performed in All
Men
?
3
Adequate
Assessment*
Blinded
No
Schmidt
1973 [20]
At the Same Time
Explicit Criteria
No
Systematically
Performed in All
Men
Follow-up Rate*
Complication Assessment
Blinded
At the Same Time
Effectiveness Assessment
Compliance/
Follow-up rate
Adequate
Comparability*
Explicit Criteria
Comparability
Total
Sample Size
Study Design*
Authors and Year of
Publication
Table 17. Quality assessment of studies comparing vas occlusion techniques with and without fascial interposition
No
?
Very Low
N/A
N/A
Very Low
Yes
No
88%/89%†
Moderate
[46]
Li et al.
1994 [32]
De Los Rios
et al.
0.39†
3
4565
0.97
Yes
No
Yes
No
Yes
No
?
No
Yes
No
Yes
?
No
55%
No
No
Yes
?
No
55%
Very Low
1
841
0.86‡
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No FI: 98.6%
No
No
Yes
Yes
No
6 weeks
High
1994-2003
[25,26]
Sokal et al.
2003 [45]
FI: 97.9%
100%
12 months
89%
*Criterion used for global assessment (see Table 2, Additional file 1).
FI: fascial interposition, N/A: not applicable.
† group A and G / group B and C.
‡ Sample size when study halted (n=841)/sample size initially planned (n=1,200).
Table 18. Results of studies comparing vas occlusion techniques with and without fascial interposition
Authors and
Year of
publication
Effectiveness (Failure)
Based on SA
Schmidt
No FI: 3.3%
1973 [20]
FI: 0%
Rhodes et al.
No FI: 6
(21.4%)
1980 [46]
Based on
Pregnancy
Comments
Complications
Hematoma
Infections
Pain
Lower failure risk with
FI when ligation
/excision performed
Granuloma
Epididymitis
Others
Total
No FI: 6.0%
No other complication
specified. Higher risk of
granulomas defined as
sperm leakage with FI
FI: 9.7%
Similar failure risk with
and without FI when only
vas transected. Very
small sample size
FI: 2 (16.7%)
Comments
Complications
unspecified
P = 0.55
Li et al.
1994 [32]
No FI (G): 14
(7.5%)
No FI (G): 1
(0.5%)
FI (A) :1 (0.6%)
FI (A) :1
(0.6%)
No FI (B): 6
(1.4%)
FI (C):10 (2.6%)
No FI (B): 2
(0.5%)
B vs C: Higher failure
risk with FI (testicular)
when ligation/excision is
performed
FI (C): 6
(1.6%)
Large variation between
centers
De Los Rios et al. No FI: 94
(29.1%)
1994-2003
FI: 57 (2.6%)
[25,26]
Sokal et al.
2003 [45]
G vs A: Lower failure
risk with FI when openend is performed
Bleeding
No FI (G): 7
FI (A) :0
No FI (B):0
No FI (G): 1
FI (A): 0
Stasis
No FI (B): 2
No FI (G): 0
FI (A) :0
FI (C): 1
No FI (B):0
FI (C): 0
FI (C): 1
No FI (G): 8
(2.2%)
FI (A): 0
No FI (B): 2
(0.5%)
FI (C): 2
(0.5%) 0
Lower failure risk with
FI when ligation
/excision performed
No FI: 53
(12.7%)
No FI: 2
(0.5%)
FI: 24 (5.9%)
FI: 2 (0.5%)
P < 0.0008
SA: semen analysis, FI: fascial interposition.
Lower failure risk with
FI when ligation
/excision performed
Time to azoospermia and
to severe oligospermia
shorter with FI
(P < 0.0001)
Higher risk of
complications due to
bleeding in group G
(open-end without FI).
Total risk of (undefined)
complications very low
Complications
unspecified
No FI: 6
(1.4%)
No FI: 2
(0.5%)
FI: 6 (1.4%)
FI: 2 (0.5%)
52 weeks
No FI: 14
(4.3%)
FI: 9
(2.6%)
No FI: 29
(6.9%)
No FI: 6
(1.4%)
FI: 41 (9.8%)
FI: 12 (2.9%)
6 weeks
No FI: 62
(14.7%)
FI: 74
(17.7%)
P = 0.23
Non significant higher
risk of complications due
to granuloma and orchiepididymitis with FI.
Same risk of hematoma
and infection