Introduction: Early surgical repair of myelomeningocele (MMC) is recommended to reduce infection rates, but severe and large defects can preclude primary closure. Many techniques of repair have been proposed to treat large defects and we report two cases of patients who underwent keystone design perforator island flap (KDPIF) for closure MMC. Methods: Retrospective analysis of two patients who underwent KDPIF for MMC repair at birth was performed. Skin and neural tube defects were large and precluded primary closure. Surgical repair of MMC consisted of reconstruction of neural placode with dissection of meningeal sac without neural damage. The opposing sliding flaps were prepared, based on randomly located vascular perforator. Skin incisions were made on the outline of the flap and continued through the subcutaneous tissues down to lumbar fascia and muscles. Closure was performed in layers and then the V-Y advancement of each end of the flap in the longitudinal axis is completed. Wound healing was satisfactory and no complications were noted. Conclusion: Early surgical repair of the defect is recommended and the neurosurgeon who deal with pediatric neurosurgery must be prepared to treat large and complex spina bifida defects. We have effectively demonstrated the use of KDPIF closure as an alternative for more complex MMC cases.

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Case Report
Neural tube defects (NTD) are congenital anomalies of neural
development with a broad spectrum of clinical manifestations,
being myelomeningocele (MMC) the most common form of spina
bifida aperta [1]. It results from defective closure of the posterior
portion of the neural tube, which is normally completed within 28
days after conception [2]. In the United States, prevalence of neural
tube defects was reported to be approximately 1:1,000 live births
and rates are higher for females [3,4]. This congenital anomaly is
associated with life-long disabilities: motor and sensory deficits,
skeletal deformities, bladder and bowel incontinence and sexual
dysfunction [5]. Hydrocephalus is frequently associated with MMC
(85-90% of cases) and the neurological focal deficits related to
brainstem dysfunction are increased by the presence of the Chiari
II malformation [6]. The results of randomized trials indicate that
dietary supplementation with folic acid can reduce the risk for spina
bifida and other NTDs [7,8]. Currently, open MMC is less common in
western countries because of maternal folate supplementation and
fortification programmes [9,10].
Early surgical repair of the defect is recommended to decrease
mortality rates by preventing cerebrospinal fluid (CSF) leakage
and related infections [11]. In small defects, treatment is readily
achieved by primary closing, but severe and large defects can
preclude primary closure [12,13]. Many techniques of repair have
been proposed to treat large defects including skin grafts, skin flaps,
fasciocutaneous flaps, muscle flaps and musculocutaneous flaps
[14]. Although effective in many cases, some of these techniques
can be complex and time demanding, even been associated with
complications such as CSF leak, flap loss, tip necrosis and wound
dehiscence [15].
Keystone design perforator island flap (KDPIF), first reported
by Behan in 2003, is a plastic surgical technique that is effective
for reconstruction of soft tissue defects in many areas of the body,
provides a very straightforward and effective skin cover, achieving
excellent aesthetic results. It is a curvilinear shaped trapezoidal
flap design, like two V-Y flaps end to side [16]. We revisited KDPIF
technique for closure of large MMCs and the pertinent anatomy
[17].
Cleiton Formentin1
*, Andrei F Joaquim2
, Helder Tedeschi3
, Cássio R do Amaral4
and Enrico Ghizoni3
1
Department of Neurology, University of Campinas (UNICAMP), Brazil
2
Department of Neurosurgeon - Neurosurgery Division, University of Campinas (UNICAMP), Brazil
3
Department of Neurosurgery Division, University of Campinas (UNICAMP), Brazil
4
Department of Plastic and Craniofacial, Sobrapar Hospital, Brazil
*Corresponding author: Cleiton Formentin, Neurosurgery Division, University of Campinas, 13083-970, Campinas-SP, Brazil
Submission: August 19, 2017; Published: November 13, 2017
Closure of Myelomeningocele Defect Using a Keystone
Design Perforator Island Flap
Tech Neurosurg Neurol
Copyright © All rights are reserved by Cleiton Formentin
Abstract
Introduction: Early surgical repair of myelomeningocele (MMC) is recommended to reduce infection rates, but severe and large defects can
preclude primary closure. Many techniques of repair have been proposed to treat large defects and we report two cases of patients who underwent
keystone design perforator island flap (KDPIF) for closure MMC.
Methods: Retrospective analysis of two patients who underwent KDPIF for MMC repair at birth was performed. Skin and neural tube defects were
large and precluded primary closure. Surgical repair of MMC consisted of reconstruction of neural placode with dissection of meningeal sac without
neural damage. The opposing sliding flaps were prepared, based on randomly located vascular perforator. Skin incisions were made on the outline
of the flap and continued through the subcutaneous tissues down to lumbar fascia and muscles. Closure was performed in layers and then the V-Y
advancement of each end of the flap in the longitudinal axis is completed. Wound healing was satisfactory and no complications were noted.
Conclusion: Early surgical repair of the defect is recommended and the neurosurgeon who deal with pediatric neurosurgery must be prepared to
treat large and complex spina bifida defects. We have effectively demonstrated the use of KDPIF closure as an alternative for more complex MMC cases.
Keywords: Spina bifida; Myelomeningocele; Neurosurgical Procedures; Keystone flap
Abbreviations: NTD: Neural Tube Defects; MMC: Myelomeningocele; CSF: Cerebrospinal Fluid; KDPIF: Keystone Design Perforator Island Flap
CRIMSONpublishers
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Case Report
ISSN 2637-7748

2. How to cite this article: Cleiton Formentin, Andrei F Joaquim, Helder Tedeschi, Cássio R do Amaral, Enrico Ghizoni. Closure of Myelomeningocele Defect Using
a Keystone Design Perforator Island Flap. Tech Neurosurg Neurol. 1(1). TNN.000504. 2017. DOI: 10.31031/TNN.2017.01.000504
Techniques in Neurosurgery & Neurology
2/4
Tech Neurosurg Neurol
Materials and Methods
Patients
We reporttheclinicalcourse and technicaldescription of two
patients who underwent KDPIF for MMC repair at birth. They had
a previous diagnosis of a lumbosacral myelomeningoceleobtained
from obstetric ultra sound and were born at our facility delivered by
planned elective caesarian section. The skin defect and the neural
tube defect were large and precluded primary closure. They were
selected by the neurosurgeons and plastic surgeons and underwent
reconstruction of the defects with KDPIF in the first hours of life.
Demographic data are presented in Table 1 and cases photography’s
are showed in Figure 1-3. Wound healing was satisfactory, with no
recorded skin flap dehiscence or necrosis, infection and CSF leak.
No complications were noted during the entire follow-up. Excellent
aesthetic outcome was achieved. One patient died from kidney
disease (renal insufficiency) and the other one was submitted to
aventriculoperitoneal shunt after the repair of the MMC defect.
Table 1: Patient demographics.
Case 1 Case 2
Birth Full term Full term
Gender Male Male
Weight 2800g 2920g
MMC Repair 1st day 1st day
Clinic Total paralyzed legs Total paralyzed legs
Previous diagnosis Obstetric ultra sound Obstetric ultra sound
Kyphectomy No Yes
Shunt 3 weeks after birth No
Complications No No
Morbidity Chiari 2
Chiari 2
Kidney horseshoe
Aortic valve disease
Figure 1: Photograph of the patient with lumbosacral
myelomeningocele.
Figure 2: (A) Intraoperative photograph showing the
reconstruction of neural placode with dissection of meningeal
sac; (B) Completed keystone repair.
Figure 3: Photograph of one child at four months follow-up
post-keystone design perforator island flap.
Surgical technique
Under general anesthesia, most of the times with nasal
intubation, patient has the umbilical vein catheterized and at least
one more peripheral vein, and if possible an arterial line is secured.
Then patient is placed in prone position with all pressure points
padded and intravenous antibiotics are administered.
Surgical repair starts as usual for MMC defects; careful
reconstruction of neural placode is performed and is closed with
prolene 6.0 single sutures, always aware to avoid dermal inclusions.
Then dissection Dura mater is performed as wide as possible
to achieve a large dural sac to allow freedom of motion of the
postneurulatedplacode and to prevent its adhesion to dura [18].
Two identical opposing keystone flaps are designed to create
a double keystone flap, based on randomly located vascular
perforator. The KDPIF has a ratio 1:1 for the width of the defect
to the width of the flap. Its length is determined by the size of the
defect.Thetrapezoidalshapedflap iscontouredalong thesideofthe
defect with 90° angle at the limits of the island flap. Skin incisions
were made on the outline of the flap and continued through the

3. Techniques in Neurosurgery & Neurology
How to cite this article: Cleiton Formentin, Andrei F Joaquim, Helder Tedeschi, Cássio R do Amaral, Enrico Ghizoni. Closure of Myelomeningocele Defect Using
a Keystone Design Perforator Island Flap. Tech Neurosurg Neurol. 1(1). TNN.000504. 2017. DOI: 10.31031/TNN.2017.01.000504
3/4
Tech Neurosurg Neurol
subcutaneous tissues to lumbar fascia and muscles. Careful teasing
of the circumferential tissues is performed to preserve the integrity
of perforators.
Closure was performed in layers, and then the V-Y advancement
of each end of the flap in the longitudinal axis is completed.
The suture was completed with 4.0 vicryl. Wound healing was
satisfactory and no complications were noted.
Discussion
Surgical treatment of patients with MMC in the early postnatal
period is required to cover exposed spinal cord and, inevitably, to
prevent CSF leakage and central nervous system infections [11,13].
Primary repair of large MMC is challenging because of the
significant tissue tension [19]. The use of excessive force to achieve
primaryclosurecancausecomplicationssuchaswounddehiscence,
necrosis and fistula, which may require reoperation [19]. Selected
thirty-two cases of MMC defects and studied the area of the defect
as a percentage of the thoracolumbar region in determination of
the surgical technique Özveren et al. [20]. In their series, it was
possible to achieve primary closure of defects occupying less than
8% of the total body area in the thoracolumbar region [20].
Many techniques have been successfully used for the
reconstruction of MMC defects that cannot be closed primarily,
including skin grafts, skin flaps, fasciocutaneous flaps and muscle
flaps [13]. In this case, we revisited the KDPIF technique for MMC
repair [17]. Behan first described the KDPIF in 2003 with an
experience of 300 successful cases, based on randomly located
vascular musculo/ fasciocutaneous perforators [16]. The viability
of the flap is then supported by the subcutaneous vascular network
and fascial and muscular perforators [16]. The flap distributes
wound tension widely and, consequently, provides significant tissue
bulk, reliable vascularity and an important geometrical versatility
[17]. studied the vascularization of this flap and the behaviour of the
skin paddle when submitted to important traction forces Pelissier
et al. [21]. Fourteen flaps were performed after skin defects created
in two fresh cadavers [21]. Longitudinal and transversal cutaneous
markings with injections of coloured solutions were performed
before and after the flap elevation to visualize the vascularization
of the flap [21]. They demonstrated the dual vascularization of
the flap [21]. The superficial vascular network was preserved by
the blunt dissection of the flap’s margins and perforators arising
from the underlying muscular tissue [21]. An analysis of 15 clinical
cases was also presented by Pelissier et al. to assess the reliability
and versatility of the KDPIF [22]. The procedure was performed
following cutaneous tumoral excision (13 cases) or injury (two
cases). No flap necrosis was observed in this study and the
patients were almost pain free in the postoperative phase [22]. In
conclusion, early surgical repair of the MMC defect is recommended
and this perforator technique can be successfully used for defects
that cannot be closed primarily. The neurosurgeon who deals
with pediatric neurosurgery must be prepared to treat large and
complex spina bifida defects. We have effectively demonstrated the
use of KDPIF closure as an alternative for more complex MMC.
Conflict of interest
Theauthorsdeclarethatthereisnoconflictofinterestregarding
the publication of this article.
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4. How to cite this article: Cleiton Formentin, Andrei F Joaquim, Helder Tedeschi, Cássio R do Amaral, Enrico Ghizoni. Closure of Myelomeningocele Defect Using
a Keystone Design Perforator Island Flap. Tech Neurosurg Neurol. 1(1). TNN.000504. 2017. DOI: 10.31031/TNN.2017.01.000504
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