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Journal of Pediatric Surgery 49 (2014) 1496–1499
Contents lists available at ScienceDirect
Journal of Pediatric Surgery
journal homepage: www.elsevier.com/locate/jpedsurg
Impact of pelvic osteotomy on the incidence of inguinal hernias in
classic bladder exstrophy
Garjae Lavien a, Heather N. Di Carlo b,⁎, Bhavik B. Shah b, John Eifler b, Eric Massanyi b, Andrew Stec c,
Paul D. Sponseller d, John P. Gearhart b
a
University of Maryland School of Medicine, Division of Urology, 22 S. Greene Street, Suite NGE19, Baltimore, MD 21201
The Johns Hopkins University School of Medicine, James Buchanan Brady Urological Institute, Division of Pediatric Urology, Charlotte Bloomberg Children’s Hospital, 1800 Orleans St.,
Suite 7203, Baltimore, MD 21287
c
Medical University of South Carolina, Department of Urology, 96 Jonathan Lucas St, CSB 644, Charleston, SC 29425
d
The Johns Hopkins University School of Medicine, Division of Pediatric Orthopedics, The Johns Hopkins Outpatient Center, 601 N. Caroline St., Room 5152, Baltimore, MD 21287
b
a r t i c l e
i n f o
Article history:
Received 2 September 2013
Received in revised form 30 April 2014
Accepted 3 May 2014
Key words:
Bladder exstrophy
Inguinal hernia
Pelvic osteotomy
a b s t r a c t
Background/purpose: The high prevalence of inguinal hernias in the bladder exstrophy population is well
documented. The authors' aim is to determine whether pelvic osteotomy reduces the incidence of primary
and recurrent inguinal hernias in patients with classic bladder exstrophy.
Methods: Using an institutionally-approved database, patients who underwent immediate or delayed primary
bladder closure between 1974 and 2012 were identified and stratified by the use of pelvic osteotomy at the
time of closure. Data were analyzed using Fisher's exact test and multivariate logistic regression analysis.
Results: One hundred thirty-six patients were identified with a median follow up of 8 years. The incidence of
inguinal hernias following closure was 25% in the osteotomy group versus 46% in the non-osteotomy group
(p = 0.017). Osteotomy was associated with a significant decrease in recurrence of inguinal hernias amongst
patients who underwent previous repair (17% versus 47%, osteotomy versus non-osteotomy, p = 0.027) and
the development of primary inguinal hernias in whom initial groin exploration was negative (20% versus 39%,
p = 0.029). Osteotomy and female sex were associated with a decreased rate of inguinal hernia development
after bladder closure while age at closure was not.
Conclusions: Pelvic osteotomy at the time of exstrophy closure decreases the likelihood of primary or
recurrent inguinal hernia development.
© 2014 Elsevier Inc. All rights reserved.
1. Background/Purpose
2. Materials and methods
Pelvic osteotomy remains a cornerstone in the surgical management of the exstrophy–epispadias complex, as it decreases tension
across the abdominal wall, reduces the pubic diastasis, and helps
restore the pelvic ring and floor to the normal anatomical configuration [1]. Patients with classic bladder exstrophy develop inguinal
hernias at higher rates compared to the general population rate of 0.8
to 4% [2]. Moreover, bladder exstrophy has been identified as a risk
factor for inguinal hernia recurrence after repair [3]. The authors
hypothesize that pelvic osteotomy stretches the inguinal ligament as
the pubic diastasis is narrowed, resulting in an increase in the
obliquity of the inguinal canal and tightening of the canal floor, which
could potentially reduce de novo hernia development as well as
decrease inguinal hernia recurrence in patients who have undergone
a previous inguinal hernia repair. In this study the authors seek to
determine the impact of pelvic osteotomy on the development of
inguinal hernia and recurrence.
Following institutional review board approval, an exstrophy epispadias complex database consisting of 1178 patients was investigated to
identify patients with a diagnosis of classic bladder exstrophy who
underwent immediate or delayed primary closure at the authors'
institution between 1974 and 2012. One hundred thirty-six patients
were identified and their medical and surgical records were retrospectively reviewed. Patients excluded from analysis included those with no
record of follow up for at least 1 month after primary closure, as well as
patients who underwent inguinal hernia repair at another hospital and
were referred to our institution for continued care. Each patient's medical
record was reviewed for gender, age at closure, repair of a hernia during or
prior to primary bladder closure, use of pelvic osteotomy at the time of
bladder closure, development of either a primary or recurrent hernia after
closure, and age at follow up. The diagnosis of an inguinal hernia was
determined by clinical examination pre- or post-operatively, or was made
intraoperatively during bladder closure.
At the authors' institution, bilateral inguinal canals are explored via the
pre-peritoneal approach during all primary exstrophy closures given the
high incidence of inguinal hernias in this patient population, along with
⁎ Corresponding author.
E-mail address: hdicarl1@jhmi.edu (H.N. Di Carlo).
http://dx.doi.org/10.1016/j.jpedsurg.2014.05.012
0022-3468/© 2014 Elsevier Inc. All rights reserved.
G. Lavien et al. / Journal of Pediatric Surgery 49 (2014) 1496–1499
the known high incidence of a contralateral patent processus vaginalis
when a hernia is present on the opposite side. When hernias are identified,
they are closed via this approach. The surgical technique for the preperitoneal approach to an inguinal hernia was described by Connolly et al.
[1]. After mobilization of the bladder, the spermatic cord is identified and
the hernia sac is dissected and tied off. Next, the spermatic cord is
mobilized laterally and sutures are placed medially between the
transversus arch and the iliopubic tract to increase the obliquity of the
inguinal canal and to tighten the internal ring. An inguinal approach is
utilized when performing hernia repair as a separate procedure, such as
when patients are undergoing other surgical procedures prior to bladder
closure, or when patients will have a delayed primary repair owing to a
small bladder template. Inguinal hernia repair through an inguinal
incision in the exstrophy population is performed in the standard fashion,
with dissection of the hernia sac from the vas deferens and spermatic cord
vessels, division, and high ligation. In patients with a wide internal ring,
sutures are placed medially to minimize the defect and to increase the
obliquity of the inguinal canal. Care is taken not to close the ring too tight
in order to ensure that vascular flow in the testicular vessels is not
compromised. This is not a concern in the female patient, as the inguinal
ring is routinely closed completely during hernia repair.
Patients were stratified into two groups for data analysis: patients
who underwent pelvic osteotomy with primary bladder closure and
those who underwent primary closure without an osteotomy. In both
groups, the presence of a hernia at the time of primary closure or prior
to definitive bladder closure was recorded. Data were analyzed for the
development of inguinal hernia after closure. Primary outcomes
assessed were the development of de novo inguinal hernias or the
development of recurrent inguinal hernias after bladder closure.
Variables were evaluated using Fisher's exact test and multivariate
regression analysis. All statistical analyses were performed with
Microsoft Excel (Redmond, Washington, USA) & Stata IC 12 (College
Station, Texas, USA). Odds ratios were used to identify variables
directly or indirectly associated with development of inguinal hernias
after bladder closure. A p-value of b 0.05 was used to determine
statistical significance.
3. Results
Upon review of the exstrophy database, 136 (98 male, 38 female)
patients with classic bladder exstrophy were identified whom had their
initial bladder closure performed at the authors' institution. Follow up
data were available on all 136 patients with a median follow up time of
8 years (range: 1 month–35 years) after initial bladder closure.
Seventy-three patients (57 male, 16 female) underwent osteotomy with primary closure while 63 patients (41 male, 22 female) did
not. Included amongst the former group were five patients requiring
hernia repair prior to primary closure because of an incarcerated
inguinal hernia. The overall incidence of inguinal hernia formation
amongst all patients with classic bladder exstrophy was 52% (males:
69%, females: 8%).
Twenty-four (33%) patients who underwent osteotomy with
primary closure and twenty (32%) patients who did not undergo
osteotomy had hernias identified during primary closure and underwent simultaneous hernia repair. Amongst these patients, 4 (17%) had a
hernia recurrence in the osteotomy group compared to 11 (55%) in the
non-osteotomy group (p = 0.027). The incidence of inguinal hernia
following primary closure amongst all patients was 25% in the
osteotomy group compared to 46% in the non-osteotomy group (p =
0.017). Fig. 1a breaks down the incidence of subsequent hernias after
primary repair in males and females. Of the 98 males undergoing
primary closure, 57 had an osteotomy while 41 did not. Sixty-six percent
of the male patients that did not have osteotomy with bladder closure
had subsequent inguinal hernia, while only 32% who had osteotomy
with primary closure had subsequent hernia. Multivariate regression
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analysis was used to determine independent risk factors for hernia
formation after closure. These results are portrayed in Fig. 1b.
Of the 39 patients that had hernia repair performed via the preperitoneal approach, 11 (28%) had a hernia recurrence. Four (13%) of
the 31 patients that underwent hernia repair via an inguinal incision
had a hernia recurrence. No patient had more than one hernia
recurrence on the same side. Eight patients developed an incarcerated
hernia after bladder closure. All patients were males in whom initial
exploration was negative. Seven patients were in the osteotomy
cohort while one patient did not undergo osteotomy. No patient with
a prior hernia repair had reported recurrence with incarceration.
4. Discussion
Since its initial description in 1958 [4], pelvic osteotomy remains
an essential component in the urologic reconstruction of classic
bladder exstrophy by alleviating tension across the abdominal wall
and bladder closure [5]. Other cited benefits include reducing the risk
of postoperative wound dehiscence, enabling successful revision of
previous failed exstrophy closures, and improved continence after
bladder neck reconstruction [6,7]. This study suggests that the use of
pelvic osteotomy reduces de novo and recurrent inguinal hernia
development in patients with classic bladder exstrophy.
Previous studies have revealed an incidence that exceeds 80% in
males and 10% in females [1,5]. This finding is suspected to arise from
an increase in intra-abdominal pressure following abdominal wall
closure as well as a lack of obliquity of the inguinal canal [1,8]. The
increased risk of inguinal hernia development in the exstrophy
population can be associated with significant morbidities, including
the risks of incarceration and strangulation of bowel, testicular
atrophy, and the potential need for further surgical procedures.
Inguinal hernia repairs in the exstrophy population are performed
either through a standard inguinal incision or in a pre-peritoneal
fashion at the time of bladder closure, which takes advantage of the
exposure afforded by dissection of the bladder template.
Inguinal hernias are a common physical examination finding seen
with classic bladder exstrophy. The authors report a 69% incidence of
inguinal hernias in males and 8% in female patients, which is similar to
previously reported outcomes in the literature. Husmann et al. [8]
found a 68% incidence of hernias in male patients who underwent
staged reconstruction. Stringer et al. [3] noted in a retrospective
review of 70 consecutive patients with classic bladder exstrophy an
incidence of 86% in male patients and 15% in female patients over a
mean follow-up period of 5.9 years. The authors have previously
reported an incidence of 82% in males and 11% in females. An increase
in the intra-abdominal pressure after bladder and abdominal wall
closure and the lack of obliquity between the internal and external
rings are thought to contribute to the increased risk of inguinal hernia
development in the exstrophy population. This conjecture is supported by Husmann et al. who noted a decreased incidence in inguinal
hernia formation in patients who underwent cystectomy with urinary
diversion versus patients that underwent a staged reconstruction. The
authors felt that placement of the bladder deep within the pelvis,
continued bladder growth after closure, and repair of the fascial defect
all contribute to these observations [8]. Similar findings of higher
incidences of inguinal hernia development have been documented in
patients after ventriculoperitoneal shunt (VPS) placement and
peritoneal dialysis catheter insertion [9], scenarios in which patients
are suspected to have higher intra-abdominal pressures after device
placement. Wu et al. [10] demonstrated an overall incidence of
inguinal hernia after VPS placement of 23 per 1000 person-years
compared to 6.13 per 1000 years in the general population. These
observations suggest that pelvic osteotomy provides a protective
benefit that counteracts the rise in intra-abdominal pressure after
primary closure of the bladder by increasing and stabilizing the
obliquity of the inguinal canal. Lower extremity immobilization
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G. Lavien et al. / Journal of Pediatric Surgery 49 (2014) 1496–1499
a
Overall:
136
underwent
primary Closure
MALES
38
underwent primary
Closure
underwent
primary Closure
41
57
Primary closure
without
Osteotomy
Primary closure
with Osteotomy
18 (32%)
Had
subsequent
hernia(s)
FEMALES
98
16
22
Primary closure
with Osteotomy
Primary closure
without Osteotomy
39 (68%)
0 (0%)
16 (100%)
No subsequent
hernia
Had subsequent
No subsequent
hernia
hernia(s)
2 (9%)
27 (66%)
14 (34%)
Had subsequent
inguinal hernia(s)
No subsequent
inguinal hernia
subsequent
inguinal
hernia(s)
20 (91%)
no subsequent
hernia
b
Fig. 1. a: Overall hernia incidence amongst males versus females. b: Multivariate regression analysis—analysis of the risk of hernia formation after primary repair.
without an osteotomy may be sufficient for minimizing undue stress
of the bladder and abdominal wall closures yet may not provide the
same degree of correction of the inguinal canal.
Stec et al. [11] used three-dimensional magnetic resonance imaging to
evaluate the pelvic floor of 19 patients with bladder exstrophy before and
after closure, seven of which were closed with an osteotomy. The findings
demonstrated that primary closure of bladder exstrophy reshapes the
pelvic floor from a box like configuration to an inwardly rotated hammock.
However, there were no significant changes in pelvic floor redistribution
between patients who underwent pelvic osteotomy compared to
those who did not. The authors did not note any postoperative changes
to the configuration of the inguinal canal when comparing the osteotomy
and non-osteotomy cohorts. The lack of an obvious radiographic
difference in regional anatomy of the inguinal and pre-peritoneal regions
may not reflect potential changes in the biomechanics that could affect
overall intra-abdominal pressure or obliquity of the inguinal canal. This
may be difficult to capture with static imaging. Further studies exploring
the rate of inguinal hernia development in other surgical techniques not
utilizing osteotomy, such as radical soft tissue mobilization [12], may give
greater insight into this pathologic process.
The role of laparoscopy in the management of inguinal hernias in
the exstrophy population has been limited. Lopez et al. [13] describes
three male patients with classic bladder exstrophy who developed
inguinal hernias subsequent to bladder closure. Each patient underwent a successful laparoscopic inguinal hernia repair without any
evidence of recurrence, with a mean follow up of 16 months. The
authors modified the standard laparoscopic approach by anchoring a
second purse string suture proximal to the internal ring and onto the
lateral abdominal wall to prevent prolapse of the hernia repair
through the ring. They cite the advantages of laparoscopy in that it is a
faster technique for addressing bilateral defects: it is a technically
straightforward procedure, it minimizes trauma to the vas deferens
and testicular vessels and offers the surgeon the ability to assess the
patency of the contralateral internal ring. This study, however, is
limited by the small cohort of patients. Larger sampling and further
long-term follow-up will be required to determine whether a
laparoscopic approach is durable in this population.
To the authors' knowledge, this study represents the first series to
assess the association between the role of pelvic osteotomy and the
development of de novo and recurrent inguinal hernias in the exstrophy
population. A major strength of this study is the management of patients
by a multidisciplinary team that includes pediatric urologists and a
pediatric orthopedic surgeon with significant experience in management of the exstrophy-epispadias complex. Nonetheless, there are
limitations. The retrospective nature of this study brings an inherent
selection bias. As a referral center for the management of the exstrophy–
epispadias complex, many patients will undergo definitive bladder
closure and subsequent genitourinary reconstruction at our institution
and elect to undergo routine follow-up with their local pediatric
urologist. The most current status of all patients may not be fully
captured. The pubic diastasis distance between the osteotomy and nonosteotomy cohorts was not measured; however, the stratification of
patients by the use of pelvic osteotomy at the time of closure reflects the
underlying severity of their diastasis. Primary closure without pelvic
osteotomy is utilized in patients with a pubic diastasis less than 4 cm or
in newborns evaluated within 48 hours who upon examination have
adequate malleability of their pelvic bones and sacroiliac ligament.
Malleability of the pelvis (which is affected by the age of the patient) and
diastasis distance are the two most important factors determining the
need for osteotomy. One could make the argument that those with a
greater degree of pubic diastasis would most likely undergo an
osteotomy. One would expect less obliquity of the inguinal canal in
these patients as the diastasis increases, which may translate into a
higher rate of inguinal hernia development. Additionally, the impact of
type of pelvic osteotomy performed on inguinal hernia development
was not assessed. Currently at the authors' institution, a combined
anterior innominate osteotomy and vertical iliac osteotomy are used to
facilitate closure. Although the data reflect both historical and
G. Lavien et al. / Journal of Pediatric Surgery 49 (2014) 1496–1499
contemporary surgical techniques, the ultimate goal of any technique is
to reduce the pubic diastasis.
5. Conclusions
Patients undergoing pelvic osteotomy at the time of bladder closure
have a lower incidence of de novo and recurrent inguinal hernia
development compared to patients in whom pelvic osteotomy was
omitted. Pelvic osteotomy may better correct and stabilize the obliquity of
the inguinal canal. A pre-peritoneal approach to the repair of inguinal
hernias in this population takes advantage of the surgical exposure
afforded during bladder closure but has a higher rate of recurrence
compared to a standard inguinal approach. These findings warrant further
research to elucidate potential changes with functional and mechanical
forces in the inguinal canal in patients after pelvic osteotomy.
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