Baylor University Medical Center Proceedings April 2017 - 154

Anatomic relation between single-incision slings and the
obturator vessels
Amy L. O'Boyle, MD, Christopher P. Chung, MD, and Wilma Larsen, MD

The risk of arterial vascular injury within the retropubic space is a
potentially life-threatening complication associated with mid-urethral
sling placement for the treatment of female stress urinary incontinence.
To determine the relationship between the major blood vessels and
a single incision sling, these slings were placed in 12 fresh female
cadavers. Following the insertion of each sling, the retropubic space was
dissected and sling placement was observed relative to the obturator
neurovascular bundle bilaterally. The distance between the most distal
aspect of each sling arm, or the point of anchoring, was measured
from the most medial aspect of the obturator vessels bilaterally. The
mean distance between each sling arm and the medial portion of the
obturator vessels was an average of 3.4 cm (range 2.0-6.0 cm) in
24 observations. Placement of the single incision sling may have a lower
risk of injuring major vessels within the retropubic space compared to
full-length mid-urethral slings.

tress urinary incontinence (SUI) is a major health
problem with a signiﬁcant health burden aﬀecting 20%
to 40% of all women, and surgery remains the most
eﬀective treatment option (1). The mid-urethral sling
(MUS) is now considered the gold standard of incontinence surgery (2). The long-term eﬃcacy and technical ease in inserting
MUSs have resulted in their widespread popularity; however,
serious and potentially fatal complications have been reported
with these procedures. It is important for any surgeon who
treats female SUI to be familiar with the anatomic relationship
between their surgical procedure of choice and the vascular
anatomy of the retropubic space.
In 2006, the third generation of synthetic slings for SUI
emerged with the development of single-incision slings (SIS),
or "mini-slings" (3). The TVT-Secur™ (TVT-S; Gynecare, Ethicon, Somerville, NJ) was described ﬁrst, and subsequently a
number of other SISs were reported. This version of sling was
described as avoiding the blind passage through the retropubic
or obturator spaces via trochars (4). Despite the lack of longterm evidence regarding its eﬃcacy, the SIS oﬀers the leastinvasive surgical treatment approach and remains a popular
choice among many surgeons who treat SUI (1, 5, 6).
Previous reports have described the vascular anatomy of the
retropubic space relative to both retropubic and transobturator
154

approaches of the MUS (7, 8). This article describes observations during cadaveric dissections following the insertion of
SISs and reviews the relevant vasculature in proximity of MUS
approaches used to treat female SUI.
METHODS
Fellows and faculty from the Walter Reed National Military
Medical Center in Bethesda, Maryland, and the Scott &White
Hospital in Temple, Texas, participated in training involving
female cadavers as part of an educational curriculum in the
surgical treatment of SUI. Local approval was granted by the
Anatomic Material Review Committees at each institution prior
to the use of these cadavers for educational purposes. Slings were
donated by Caldera Medical (Agoura Hills, CA; Desara™) and
Boston Scientiﬁc (Natick, MA; Solyx™).
A total of 12 SISs were placed according to manufacturer
guidelines by the ﬁrst author. Initially, an incision of approximately
1.5 cm was made along the anterior vaginal wall at the level of the
mid-urethra in each cadaver. Next, a tunnel was created sharply to
the interior portion of the inferior pubic ramus at about a 45-degree
angle from the midline to place each sling arm bilaterally. After each
sling was placed, the retropubic space was inspected by exposing
the space of Retzius via a low transverse abdominal incision.
Each sling was inspected at the most lateral aspect of each
point of ﬁxation into the obturator internus fascia. The distance
between this anchoring point of the sling arm and the medial
aspect of the obturator neurovascular bundle was measured and
recorded bilaterally. A total of 24 measurements were performed
with a ﬂexible plastic ruler marked in 1 mm increments. Each
measurement was taken by one author and conﬁrmed by a
second prior to recording to the nearest 0.5 cm. Dissection,
measurement, and interpretation of the observations were
shared, discussed, and interpreted by all of the authors.
From the Division of Urogynecology, Department of Obstetrics and Gynecology,
Walter Reed National Military Medical Center, Bethesda, Maryland (O'Boyle);
the Division of Urogynecology, City of Hope Duarte, Duarte, California (Chung);
and the Division of Urogynecology, Department of Obstetrics and Gynecology,
Baylor Scott and White Health and Texas A&M Health Science Center College of
Medicine, Temple, Texas (Larsen).
Corresponding author: Wilma Larsen, MD, Department of Obstetrics and
Gynecology, Baylor Scott & White Health, 2401 South 31st Street, Temple, TX
76508 (e-mail: Wilma.Larsen@BSWHealth.org).
Proc (Bayl Univ Med Cent) 2017;30(2):154-156

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