Cleft palate repair with the use of osmotic expanders: a preliminary

Journal of Plastic, Reconstructive & Aesthetic Surgery (2007) 60, 414e421
Cleft palate repair with the use of osmotic
expanders: a preliminary report
Kazimierz F. Kobus a,b,*
a
Department of Plastic Surgery, Medical University in Wroclaw, 50-367 Wroclaw, Poland
Department of Plastic Surgery, Specialistic Medical Center in Polanica Zdroj,
Jana Pawla II Street 2, 57-320 Polanica Zdroj, Poland
b
Received 30 August 2005; accepted 1 January 2006
KEYWORDS
Cleft palate;
Osmotic expanders;
Tissue expansion;
Palatoplasty
Summary A new method of cleft palate repair by expansion of tissue by means
of osmotic expanders implanted in the first stage of treatment is described. Selfexpanding expanders manufactured by OSMED (Ilmenau, Germany) were implanted
under the mucoperiosteal layer of the hard palate, on purpose to generate more
tissue and provide facility for palate repair performed 24e48 h later.
Nineteen children aged from 2 to 3 years were operated from January 2004 to 15
April 2005. In clefts < 10 mm, tissue repair was possible without relaxing incisions.
In 11 patients with clefts > 10 mm, cleft palate repair was more difficult and the
outcomes were less favourable. Despite more generous dissection of the neurovascular bundles and other adjunctive measures such as mucosal VeY plasty [Bardach
J, Salyer K. Surgical techniques in cleft lip and palate. Chicago, London: Year Book
Medical Publishers, Inc.; 1987.] and suturing of the mucosal grafts at the border of
the hard and soft palate, seven 2e4 mm fistulae were noted, however.
Concluding, in spite of some shortcomings and unacceptable rate of fistula in
wide clefts, the above-presented method seems to be an attractive concept. Despite some technical problems related mostly to still tested optimal filling phase,
tissue expansion makes palate repair easier, probably without relaxing incisions
and bone denudation. Consequently, some adverse effects on facial growth may
be reduced. So far, there is no evidence for it, however, and since this is a preliminary report, there is a need for longer observations and larger material.
ª 2007 The British Association of Plastic Surgeons. Published by Elsevier Ltd. All
rights reserved.
* Department of Plastic Surgery, SCM in Polanica Zdroj, Jana
Pawla II Street 2, 57-320 Polanica Zdroj, Poland. Tel. þ48 74
86 21 151 Fax: þ48 74 86 21 158.
E-mail address: prof.k.kobus@chirurgiaplastyczna.scm.pl
URL: http://www.scm.pl
Following cleft palate repair factors that might
lead to hypoplasia and deformity of the maxilla
include extensive dissection of the tissues and the
healing of wounds by secondary intention. This is
1748-6815/$ - see front matter ª 2007 The British Association of Plastic Surgeons. Published by Elsevier Ltd. All rights reserved.
doi:10.1016/j.bjps.2006.01.053
Cleft palate repair with the use of osmotic expanders
especially so after Von Langenbeck’s, Veau’s, Peet
and Wardill’s methods,1e4 in which the bones are
denuded as a result of mucoperiosteal flaps transposition and the use of relaxing incisions. As the
result, the healing of the wounds occurs through
granulation with subsequent, damaging effect of
the post-surgical scars.5e9
Similar results, though slightly less harmful, are
associated with the use of vomer flaps,10e15 in
which denudation of the vomer and nasal septum
may increase its deviation, narrow the nasal ducts
and exert an inhibitory effect on maxillary development too.16
Among various methods of so-called saving or
low-traumatic management,12e15,17e21 operation
on the soft palate with subsequent closure of the
hard palate cleft was delayed until a later age is
considered the most effective.22e25 However, despite a proven protective effect on the maxilla,
the quality of speech and the prolonged therapeutic process are drawbacks.26,27 Thus despite
numerous and significant improvements, such
as a reversed sequence of treatment,18 Dunn’s
method,28e31 supraperiosteal dissection according
to Leenstra et al. modality,32 Perko VeY plasty33
or our own surgical method with the use of an extended vomer flap,12e14 the problem remains.
Since the main problem lies in the deficiency of
tissue, the bulk of which should be increased, 8
years ago the author undertook the first trials to
insert mini-expanders filled with physiological
saline for mucoperiosteal tissue expansion. This
resembled to some extent the method introduced
by De Mey et al.34 who used a custom-made expander in the treatment of palate fistula in an
8-year-old child. The program was abandoned
due to technical problems and it was not until
osmotic expanders were introduced and idea was
resumed.
Patients and methods
The osmotic expanders are self-filling devices consisting of an osmotic active hydrogel (copolymer
from methylmethacrylat and N-vinylpyrrolidone
made by OSMED gmbh according to the requirement
of German law/Medizinproductegesetz).35
It allows tissue expansion without the use of
injection. Once implanted they absorb body fluid,
which leads to a predetermined volume and size.
The properties of the custom-made cigar like
expanders were determined before and after
swelling in 0.9% NaCl solution, to be volume: 5.2
(final volume/initial volume) and linear expansion:
1.75 (final dimension/initial dimension).
415
According to manufacturer’s data, the maximum volume is achieved after 24e48 h. The material is nontoxic without any systemic effects in
several studies.
From 8 January 2004 to 15 January 2005, hard
palate mucoperiosteal tissue expansion was used
as a method of treatment in 19 children aged from
2 to 3 years, with isolated (5), unilateral (8)
and bilateral (6) palatal clefts. An average width
of the clefts measured on the border of the soft
and hard palate was 11.7 mm.
All the patients were operated by using a
two-stage procedure under general intratracheal
anaesthesia. Osmotic expanders were used as
temporary implants which remained in the body
from 1 to 2 days. Before the treatment cleft width
measurements on the border of the soft and hard
palate as well as dental cast analysis were done in
all the patients.
The palate repair with the use of osmotic
expanders has been approved by Ethical Committee of Medical Academy in Wroc1aw.
Cleft palate surgery
Stage 1
After insertion of the mouth gag and injection of
0.25% solution of xylocaine with 1:200 000 epinephrin, the palatal mucosa and periosteum were
incised bilaterally at the length of 1 cm. Initially
the incision was performed immediately behind
the alveolar process, later it proceeded along the
edge of the hard palate. The hard palate was dissected subperiosteally with a curved raspator as
far as the alveolar process and the posterior
margin of the palatal plate.
Custom-made osmotic expanders manufactured
by OSMED with a 5-fold swelling factor were
inserted into the formed tunnels. The initial size
of the expanders was tailored according to the age
of the patient, size of the palate as well as the
planned scope of its action. Three types of
cylindrical expanders and an hourglass expander
were used as follows: 15 6, 9 6 and 12 4 mm,
which expanded to the size of 25 10, 15 10 and
20 6.7 mm, respectively.
The expanders were most commonly inserted
into the posteriomedial part of the hard palate. In
five cases, double expanders, 9 6 and 12 4 mm,
on both sides of the cleft were inserted. The
wounds were closed with 4/0 Vicryl sutures.
Until the time of the second operation, the
patients were fed parenterally. The oral cavity was
checked every 3 h in case the expanders discharged spontaneously and to prevent possible
asphyxia.
416
The second stage of treatment was performed
after 24e48 h depending on the condition of the
expanded tissue. In the initial period, when only
15 6 mm expanders were used, the treatment
protocol according to which the osmotic expanders
were left for 48 h had to be changed. Faster than
expected increase of the bulk of the tissue and resultant excessive tension necessitated operation
after 24 h in fear of spontaneous discharge of the
expanders and/or necrosis of the tissue. Cyanosed
or pale tissue as well as significant tension that
might eventually result in dehiscence of the wound
was regarded as an indication for intervention on
the day after the first procedure. In patients with
normal-looking tissues, the second stage operations were performed after 48 h.
After the removal of the sutures and swelled
expanders, the margins of the soft palate were
incised and dissected, the aponeurosis was cut
transversely and the palatine muscles were translocated backwards. In narrow clefts, delicate
dissection of the tissue around the palatal vessels
was enough to close the cleft by means of 5/0 and
4/0 Vicryl sutures (Fig. 1). The wider clefts were
managed by dissection of the neurovascular bundle36 from small, stab incision (3) and one
patient had VeY plasty with mucosal flaps
according to Perko’s method.33 Dissection of the
neurovascular bundle was associated with hamulus
processes infraction in one patient and with detachment of the tendons of the tensor veli palatini
muscles in another one (Fig. 2). Despite quite important gain of expanded tissues in three recently
repaired wide clefts the simple suturing on the oral
side has been considered too risky due to excessive
tension. Therefore, the small mucosal grafts were
applied.
Results of treatment
Cleft repair according to generally accepted
criteria was obtained in all patients. No tissue
necrosis occurred, and to our surprise, even badly
cyanosed tissues regained their colour almost
immediately after the removal of expanders.
Among eight patients with clefts < 10 mm, two
patients developed mini-fistulae on the border of
the soft and hard palate. In 11 clefts more than
10 mm wide (mean, 14.2) as measured at the level
of the posterior nasal spines the results were less
satisfactory, however. Despite the adjunctive
procedures described above, the mini-fistulae
(2e4 mm) were noted in seven of the abovediscussed cases (Fig. 3).
Apart from this, both the surgical procedures
and the post-operative course were uneventful.
K.F. Kobus
No complications were observed in early follow-up
examinations carried out after 4e6 months.
Discussion
Tissue expansion is a popular and effectively used
modality of treatment. Therefore, the idea of hard
palate mucosal augmentation seems to be justified
especially as palatal tissue elasticity and the
stretch-relaxation phenomenon37,38 allow closure
of cleft defects that are even wider than those
predicted on a geometric basis alone. According
to Bardach and Salyer37 and Furlow,39 many palatal
defects can be closed without exposing bare bone
because of various angulations of the palatal
shelves and downward rotation of the mucoperiosteal layer. For example, when both palatal shelves
are 10 mm in actual width and are angled at 60
degrees with respect to the horizontal plane of
closure-equation C ¼ A(1 cos(x)) þ B(1 cos(y))
shows that a 10-mm palatal cleft can be closed
without tension by rotation of the mucoperiosteal
tissues from their initial position on the palatal
shelves into the horizontal plane (Fig. 4).37
Despite the calculations, the above-described
method can be applied to narrow clefts only,
because .‘while the absence of relaxing incisions
has theoretical merit, in practice the closure of
a wide cleft in this manner is probably beyond the
skill of most of us’.40
Therefore, using expanders and generating
additional palatal tissue may enhance cleft repair
and reduce the extent of the surgery.
In palate clefts, difficulties in maintaining conventional expanders as well as the abundance of
microorganisms in the oral cavity do not favour this
method and for that reason first trials of tissue
augmentation were limited to short-lasting expansion during the same surgical procedure. The sofar used methods included several times repeated
injections of 1% solution of lignocaine with epinephrine to the soft palate41 as well as tissue
expansion at the hard and soft palate border by
means of 5 cc Foley’s catheters.42 In view of lack
of further reports published on that subject, it
may be assumed that the procedures fell into
disuse and were abandoned, as with our own trials
of using classical mini-expanders.
The use of self-inflating hydrogel expanders
seems to solve these problems, provided that
some difficulties associated with precise calculation of a desirable volume and expansion time are
secured. After implantation, the expanders cannot
be controlled, risking inadequate tissue expansion or damage caused by excessive tension and
Cleft palate repair with the use of osmotic expanders
417
Figure 1 (Above, left) Unilateral incomplete cleft palate before treatment. (Above, right) Expanded mucoperiosteal tissue almost closing hard palate gap. (Below, left) Osmotic hydrogel expanders before and after swelling. (Below, right) The palatoplasty performed without any relaxing incisions.
compromised blood supply. Although we did not
experience such complications, recently we decided to study this problem thoroughly on the
model of expanded rabbit’s palatal tissue.
In the initial calculations of their volume, data
from trials with the classical mini-expanders were
helpful. As far as swelling time is concerned, the
technical conditions associated with the properties
of hydrogels had to be accepted. According to
parameters of the manufacturer OSMED, a 5-fold
increase in the volume of the expanders occurs
within 24e48 h, with 98% of the volume reached in
the first 24 h.35
Such super-quick expansion of tissues has its
advantages and disadvantages.43,44 Disadvantages
include the risk of necrosis and breaking the sutures. Moreover, an express, thus probably incomplete reorganization of the collagen fibres, may
limit the efficacy of tissue expansion and possibly
promote its secondary contraction. On the other
hand, however, leaving the expanders in place
for such a short time reduces both the risk of infection and the costs of treatment.
Despite an unquestionable disadvantage of twostaged operation in a short time, new technical
possibilities associated with the use of osmotic expanders may be of interest to clinicians working with
cleft patients, if the following conditions are fulfilled.
Apart from the above-described technique, it
seems desirable to improve the method of tissue
418
K.F. Kobus
Figure 2 (Above, left) Unilateral cleft palate operated on using four osmotic expanders. Palatal view after tissue
expansion and removal of sutures. (Above, centre) Note exposed expander. (Above, right) Swelled cylinder-like
expanders against the background of the palate. Immediate result (below, left) and final outcome of palatoplasty
without any relaxing incisions (below, right).
expansion on the hard and soft palate border as
well as in the area between the palatine foramen
and the alveolar process, where a narrow and
compact space makes insertion of the expanders
difficult. Blunt dissection accomplished from a minute incision is helpful in the area posterior to the
maxillary tuberosity, but according to Ross8 and
many others this sensitive region should not be
violated due to the risk of midfacial growth
aberrations.
The susceptibility of tissue to expansion may be
increased by dissecting the region of the nasal
spine as well as medial and posterior palatine
margins. This requires solely prolonged or full
incision along the cleft fissure. The problem is
that the swelling of the expanders acts also
beyond the mucoperiosteal cover of the hard
palate towards the nasal mucosa and sutured after
expander insertion wound margins, which can be
unable to withstand the excessive tension. That is
the reason why only small expanders (12 4 and
9 6 mm) with a lower efficacy can be used
safely. Limited expansion of the mucosa and
periosteum does suffice to close a majority of
hard palate clefts, but may be inadequate in
clefts > 10e12 mm, however. What remains in
such cases is the above-mentioned elevation of
the hard palate mucoperiosteal flaps to the horizontal plane as proposed by Furlow,39 or e as
a last resort e the two-flap incision and transposition, followed by partial closure of lateral incisions
as proposed by Bardach and Salyer.37
As evidenced by first clinical trials, an extensive
tension and risk of wound disruption on the oral
side cannot be prevented by suturing of minimucosal graft at the border of the hard and soft
palate. Though due to delay phenomenon, an
expanded and precisely repaired nasal layer makes
an excellent vascularised bed, and a relatively
loose hard palate tissue adapts well to this area of
concavity by quilted suture and tongue pressure,
the healing-in of the mucosal grafts is poor.
Cleft palate repair with the use of osmotic expanders
419
Figure 3 (Left) Severe unilateral cleft palate with 20 mm gap measured at the level of the posterior nasal spine.
Two, 10 mm long relaxing incisions were made to avoid undue tension. Result of repair 6 months later. (Right)
Note small fistula.
Moreover, the gain due to horizontal transposition
of tissue is strongly reduced in such cases.
Since it is a preliminary report, there are still
many doubts and dilemmas. So far, the body fluids
absorption and swelling pressure were investigated
on the model of an expanded rat’s skin only.45 As
the skin differs from the palate tissue, and transfer
of experimental data to human subjects is rather
limited, there is a need for serious clinical investigations such as serial biopsies, blood flow measurements and thorough clinical observations. So
far, the few clinical reports46e49 are not very useful alas, because they apply to the use of osmotic
implants for breast reconstruction, enlargement of
anophthalmic sockets and closure of skin defects
in other parts of the body. Moreover, according
to Ronert’s et al. method46 the filling phase was
completed in 40e60 days, while the hard palate
tissue expansion takes 1e2 days only.
Figure 4 Apparent position and downward rotation of
the mucoperiosteal hard palate tissues according to
Bardach’s concept (modif.).
As it has been mentioned before, apart from
supposed tissue necrosis and breaking of the
wounds, such super-quick expansion can produce
less efficient augmentation of tissues. According to
Wee et al. experiments50 with the use of classic
expanders an intraoperative tissue expansion performed in pigs gave a true gain in area of 7.4%,
while continuous tissue expansion performed
over a 3-day period produced a 22% gain. Therefore, recent introduction of the silicone membrane
that encloses the expander and leads to a slower
(2e3 days), more gradual and consisting swelling
seems to be optimal solution.
Despite an unacceptable so far rate of fistula,
expected improvements and refinements make
the new philosophy of cleft palate repair very
attractive, because replacement of tissue transposition with its augmentation should produce
less scars and trauma. And since the principal
growth inhibitor seems to be the quantity and
distribution of scar tissue that forms after surgery
the beneficial effect of this modality may be
achieved.
Finally it should be stressed that at the beginning, to be on the safe side, osmotic expanders
were used exclusively in the treatment of children
scheduled or referred to us at the age of 2e3
years. For about a year, however, the palate and
vomer tissue expansions are used also in the
treatment of 6-month-old children. So far the
results seems to be better, but it would be
definitely too early for any conclusions.
420
Acknowledgments
The author thanks the OSMED gmbh for gratuitous
supply of order made to osmotic expanders. The
author would also like to acknowledge Drs
M. Wysocki and I. Siewiera for their assistance.
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