Baylor University Medical Center Proceedings April 2017 - 155

Table 1. Distance between single incision sling and obturator
vessels in 12 female cadavers
Sling

Insertion

Boston Scientific
(Solyx)

4.5

Mean ± SD

3.6 ± 1.4

3.8 ± 0.7

2.5

3.5

Caldera Medical
(Desara)

Both (n = 24)

Right (cm) Left (cm)

Right and left

3.7 ± 1.1

Mean ± SD

3.0 ± 0.8

3.3 ± 0.8

3.1 ± 0.8

Mean ± SD

3.3 ± 1.2

3.5 ± 0.8

3.4 ± 1.0

RESULTS
As shown in Table 1, the mean distance in the 24 measurements
was 3.4 cm (range 2.0-6.0 cm). Distances for the right side did not
diﬀer between the two devices (P = 0.15 using unpaired t test). In
addition, distances between sides did not diﬀer in 24 observations
(P = 0.54 using unpaired t test).
DISCUSSION
Surgical simulation in conjunction with cadaver dissection
remains a valuable training tool in pelvic surgery, particularly
with the rapidly evolving armamentarium of options to treat
SUI. Table 2 compares the distance found in this study to
that found in two other reports (8, 9). Muir et al described
the distance between the lateral margin of the TVT needle to
major vessels in 10 cadavers, highlighting the unique aspects
of the blind upward passage of the TVT trochar through the
Table 2. Mean distance between type of mid-urethral
sling and the retropubic vascular structure

Report

Mean distance (cm)
to obturator vessels
(range)

Retropubic tension-free
vaginal tape

Muir et al (n = 20)

3.2 (1.6-4.3)

Transobturator tape

Zahn et al (n = 14)

1.8 ± 0.7 (0.8-3.2)

Inside-out

1.3 ± 0.4

Outside-in

2.3 ± 0.4*

Current report (n = 24)

3.4 ± 1.0 (2.0-6.0)

Type of mid-urethral sling

Single-incision sling

*P < 0.001 for inside-out vs. outside-in using t test; mean difference = 1.0 ± -0.6 cm.

April 2017

retropubic space and demonstrating that small deviations at the
point of trochar insertion could lead to a magniﬁed deviation
at the exit point (8). Zahn et al also reported the distance
of both the inside-out and the outside-in techniques of the
transobturator tape to the obturator canal in 7 cadavers (9).
In the current report, the average distance between the most
lateral aspect of the SIS tape and the obturator vessels was 3.4
cm in 24 observations. This SIS distance could have a lower
risk of injuring obturator vessels compared to the TVT and the
outside-in and inside-out TVT-obturator slings. It is important
to note that all other major structures in reach of the TVT have
been injured by the TVT, to include the superﬁcial epigastric,
the inferior epigastric, the external iliac, bowel, bladder, and
urethra (10-13). These structures are unlikely to be injured by
a SIS procedure.
Gynecare removed the TVT-Secur, the ﬁrst SIS, from the
market in June 2012. Although the products used in this report
have also since been removed, other newer and reﬁned SISs are
still available for the treatment of female SUI. At the present
time, quality long-term data regarding the eﬃcacy of currently
available SISs and comparative data regarding various delivery
and anchoring mechanisms are not available. Despite this,
the potential for successfully treating female SUI with a more
cost-eﬀective approach continues to make SISs attractive to
many surgeons (5). A meta-analysis of trials that compared
SISs to standard MUSs showed no signiﬁcant diﬀerence in both
subjective and objective cure rates, after excluding trials that
included the TVT Secur (14).
As with MUSs, SISs have also been associated with
complications, including vaginal mesh exposure, groin pain,
persistent urinary incontinence, bladder perforation, urethral
obstruction, and signiﬁcant bleeding complications (7, 15-17).
The vessel known as the corona mortis, or "crown of death,"
has been reported as a source of signiﬁcant hemorrhage following the placement of the TVT Secur (10, 11). This anomalous
anastomosis between the obturator and epigastric vessels may
be at risk when a device closely skims the periosteum of the
pubic ramus, a characteristic unique to insertion of the original
TVT Secur. Newer devices seem to have evolved to decrease the
likelihood of such injuries.
As the need for surgical treatment of SUI continues to grow,
so will the demand for more safe and cost-eﬀective treatment
options. Although venous bleeding into the retropubic space
secondary to blind insertion of the MUSs may be unavoidable,
catastrophic arterial hemorrhage should be avoided with proper
training and familiarity with the retropubic anatomy. Surgeons
should have a clear understanding of the vascular relationships
to their MUS sling of choice.

Garely AD, Noor N. Diagnosis and surgical treatment of stress urinary
incontinence. Obstet Gynecol 2014;124(5):1011-1027.
Nilsson CG, Palva K, Aarnio R, Morcos E, Falconer C. Seventeen
years' follow-up of the tension-free vaginal tape procedure for female
stress urinary incontinence. Int Urogynecol J Pelvic Floor Dysfunct
2013;24(8):1265-1269.
Lucente VR, Ephraim SN. Diagnosis and surgical treatment of stress
urinary incontinence. Obstet Gynecol 2015;125(4):979.

Anatomic relation between single-incision slings and the obturator vessels

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Table of Contents for the Digital Edition of Baylor University Medical Center Proceedings April 2017