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The Palatal Island Flap for Reconstruction of Palatal and Retromolar Trigone Defects Revisited
Eric M. Genden, MD;
Bryant B. Lee, MD;
Mark L. Urken, MD
Arch Otolaryngol Head Neck Surg. 2001;127:837-841.
ABSTRACT
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Background Although a host of local soft tissue flaps have been described for the
reconstruction of postoperative palatal defects, tissue-borne palatal obturators
remain the most common form of rehabilitation of these defects. The palatal
island flap, first applied to the reconstruction of the retromolar trigone
and palatal defects, was first described by Gullane and Arena in 1977. This
single-staged mucoperiosteal flap offers a reliable source of regional vascularized
soft tissue that obviates the need for prosthetic palatal rehabilitation.
Objective To describe a series of 5 cases in which the palatal island flap was
used as a primary palatal or retromolar reconstruction.
Methods We have retrospectively reviewed 5 consecutive cases between March 1998
and August 1999 wherein palatal island flaps were used for the primary reconstruction
of postablative palatal defects. Each case was reviewed for primary pathologic
findings, postoperative wound complications, postoperative speech and swallowing,
and donor site morbidity. Selection of this reconstructive technique was based
on the size and location of the defect and the assessment by the surgeon that
the arc of rotation and amount of residual palatal mucosa were appropriate.
Results Six local palatal island flaps were performed on 5 patients who had
not undergone irradiation (1 patient underwent bilateral flaps). The primary
pathologic findings included T1 N0 squamous cell carcinoma, T4 N0 squamous
cell carcinoma, T2 N0 low-grade mucoepidermoid carcinoma, pigmented neurofibroma,
and T2 N0 low-grade clear cell carcinoma. All of the lesions were located
on the hard or soft palate or the retromolar trigone, and the average defect
size was 7.2 cm2. All 5 patients began an oral diet between postoperative
days 1 and 5 (mean, 2 days), and all patients were discharged home without
postoperative donor site or recipient site complications between days 1 and
6 (mean, 3 days). Donor site reepithelialization was complete by 4 weeks in
all 5 patients.
Conclusions The palatal island flap offers a reliable method of primary reconstruction
for limited lesions of the retromolar trigone and hard and soft palate. The
mucoperiosteal tissue associated with this flap is ideal for partitioning
the oral and nasal cavities and obviates the need for prosthetic palatal obturation.
INTRODUCTION
DURING THE past several decades, the range of reconstructive techniques
to restore oral cavity defects has increased significantly. Although tissue
from distant sites can be transferred by microvascular techniques, one of
the basic premises of reconstructive surgery is to use the simplest and safest
technique that accomplishes the desired goal, which is to restore defects
using "like tissue." In addition, the surgeon must walk a fine line between
borrowing the ideal tissue and incurring secondary morbidity associated with
the donor site from which that tissue is harvested. The oral cavity remains
the ideal site from which to obtain tissue to solve this reconstructive challenge,
but it is also imperative to make certain that the secondary deformity does
not cause additional functional problems for the patient.
Reconstruction of the palate or retromolar trigone after ablative surgery
is a challenging problem. Although superficial defects may be closed primarily,
allowed to heal by secondary intention, or resurfaced with a split-thickness
skin graft, defects that involve the periosteum or those that enter the sinonasal
cavity usually cannot be optimally reconstructed in these manners. A variety
of locoregional flaps have been described to resurface these areas; however,
none has been as popular as the tongue flap.1
Guerrero-Santos and Altamirano2 described the
central mucosal tongue flap to reconstruct palatal defects. Despite its ease
of rotation and apparent abundance as a source of reconstructive tissue, the
tongue is clearly the most important organ in the oral cavity with respect
to function, and borrowing from the tongue may cause significant functional
deficits that might otherwise be avoided through selecting an alternative
option.
Consequently, a host of alternative reconstructive options have been
proposed for oral cavity reconstruction. Local and regional flaps, such as
the buccal mucosal flap,3 the forehead flap,1 and the temporalis muscle and temporoparietal fascial
flaps,4-5 have been successfully
used for oral cavity reconstruction. Similarly, fasciocutaneous free flaps
have also been used for retromolar trigone and palatal reconstruction.6 Although each of these reconstructive options offers
its own distinct advantages, the goal of using "like tissue" for oral cavity
reconstruction remains particularly appealing. Oral mucosa that is well vascularized,
sensate, and similar in thickness is an ideal source of donor tissue. Although
buccal mucosa flaps offer some of these characteristics, the limited mobility
of these flaps often restricts their application.
In 1977, Gullane and Arena5 described
the total palatal island flap as a versatile alternative for oral cavity reconstruction.
Originally introduced by Millard7 in 1962 as
a palatal lengthening technique for cleft palate restoration, high complication
rates limited its popularity. An increased incidence of midface growth deformity
and subsequent malocclusion was associated with this flap when applied to
the pediatric population. Gullane and Arena,8
however, recognized a potential for the application of this flap for postablative
oral cavity reconstruction in the adult population. Initially reported for
the rehabilitation of defects of the palate, retromolar trigone, cheek, and
tonsillar fossae, subsequent reports demonstrated an expanded utility of the
palatal island flap by transferring nearly the entire hard palate mucosa based
on a single neurovascular pedicle.8 The secondary
defect of exposed palatal bone is resurfaced by new mucosa over several weeks,
leaving little or no detectable deformity.
We report 5 cases in which the palatal island flap was used for the
single-staged reconstruction of either a palatal or retromolar trigone defect.
This report will include a review of the anatomy and technique for raising
the palatal island flap.
The surgical anatomy and technique for raising the palatal island flap
are as follows. The hard palate is covered by mucosa, which is densely adherent
to the underlying periosteum. The periosteum, in turn, is firmly attached
to the palatal bone through the fibrous pegs of Sharpey. The vascular supply
to the palate is primarily derived from the paired greater palatine arteries
that arise from the descending palatine artery, a branch of the internal maxillary
artery. The neurovascular pedicle associated with the palatal island flap
exits from the greater palatine foramen, which is located adjacent to the
second molar along the lateral aspect of the transverse suture line, which
separates the maxillary shelf from the palatine shelf posteriorly.
The midline longitudinal raphe divides the palate in half; however,
a single vascular pedicle can supply the entire palatal flap.8
Innervation of the palatal mucosa is derived from branches of the second division
of the trigeminal nerve. The sensate nature of the palatal island flap provides
an added functional benefit to oral cavity reconstruction.
In raising the palatal island flap, incisions are made according to
the amount of donor tissue required to resurface the oral defect. Incisions
can be made at the junction of the hard and soft palate and within 5 mm of
the dentition. This allows for harvesting a flap that can be rotated 180°
without strangulation of the vascular pedicle. Like the paramedian forehead
flap, the palatal island flap is unique because its vascular pedicle traverses
a bony canal. Its mobility is, therefore, compromised by this anatomic restriction.
However, further reach can be obtained by removing the hamulus of the pterygoid
plate; however, this is seldom necessary. The donor site is allowed to heal
by secondary intention, which occurs 3 to 4 weeks after harvest. The growth
and coverage of the hard palate defect with new mucosa occurs rapidly. Because
this takes place over the hard palate surface, contracture and, therefore,
donor site deformity are limited. Healing by secondary intention over the
hard palate is a different phenomenon than what occurs over the soft palate
tissue bed. Postoperative discomfort can be alleviated by covering the denuded
palate with a prefabricated prosthesis.
METHODS
We retrospectively reviewed 5 consecutive cases of primary oral cavity
reconstruction using palatal island flaps performed in the Department of Otolaryngology–Head
and Neck Surgery at the Mount Sinai Hospital in New York. The cases reviewed
were performed over a 15-month period from March 1998 to August 1999. Each
case was evaluated after a minimum of 1 year for pathologic findings, defect
size, postoperative wound complications, postoperative speech and swallowing,
and donor site morbidity.
RESULTS
A total of 6 local palatal island flaps were performed on 5 patients
(1 patient underwent bilateral flaps) during a 15-month period for primary
reconstruction of postablative defects of the palatomaxillary complex and
the retromolar trigone. None of the 5 patients had received preoperative radiation
therapy. Final pathologic findings included T1 N0 (1 patient) and T4 N0 (1
patient) squamous cell carcinomas, T2 N0 low-grade mucoepidermoid carcinoma
(1 patient), pigmented neurofibroma (1 patient), and T2 N0 low-grade clear
cell carcinoma (1 patient) (Table 1).
Three lesions were located on the hard palate, creating a defect that communicated
with the maxillary antrum; 1 lesion was located on the soft palate; and 1
lesion was located on the retromolar trigone. The average defect size for
all 5 sites was 7.2 cm2 (range, 4-16 cm2). There were
no intraoperative complications during the flap harvest nor was there any
donor site morbidity associated with the 6 flaps. One patient underwent bilateral
palatal island flaps for the rehabilitation of a soft palate defect. Four
of the 5 patients began a liquid diet on postoperative day 1 and started a
regular diet between postoperative days 1 and 5 (mean, 2 days). The oral nutrition
in the patient with the retromolar trigone defect was delayed until the fifth
postoperative day. All 5 patients were discharged home without postoperative
donor site or recipient site complications between days 1 and 6 (mean, 3 days).
Donor site reepithelialization was completed by 4 weeks in all 5 patients.
Both flaps and the new mucosa that grew over the hard palate regained sensitivity.
There were no flap dehiscences, flap necroses, postoperative infections, or
associated long-term donor site morbidity.
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Palatal Island Flap Reconstruction
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CASE PRESENTATIONS
Case 1
This patient was a 67-year-old woman with a medical history significant
for radiation therapy for teenage acne who presented with complaints of persistent
tenderness in the region of the posterior maxillary alveolus. A computed tomographic
scan of the area revealed an osteolytic lesion involving the posterior alveolar
ridge (Figure 1). A biopsy specimen
of an exophytic lesion measuring 2.5 x 2.0 cm was positive for squamous
cell carcinoma (T4 N0 M0). Intraoperatively, the resection of the maxillary
tubercle and adjacent retromolar trigone mucosa left a 3 x 3-cm infrastructure
maxillectomy defect that communicated with the maxillary cavity (Figure 2 and Figure 3).
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Figure 1. Case 1. An axial computed tomographic
scan demonstrating the lesion (left side) and erosion of the posterior alveolar
ridge.
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Figure 2. Case 1. Intraoral photograph demonstrating
the posterior palatal and retromolar trigone defect. The defect communicated
with the maxillary sinus.
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Figure 3. Case 1. Photograph demonstrating
the surgical specimen.
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The defect was reconstructed using a contralateral-based palatal island
flap (Figure 4). The postoperative
course was unremarkable. The patient was maintained on enteral nutrition via
a nasogastric tube for 4 days and began a regular diet on day 5. The patient
was discharged on postoperative day 6. At a 4-week follow-up evaluation, the
donor site was well healed and the patient denied any donor site discomfort
(Figure 5). Six months following
surgery, the patient developed an ipsilateral neck lymph node for which a
modified neck dissection and adjuvant radiotherapy were performed. The patient
currently remains free of disease at both the primary site and the neck.
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Figure 4. Case 1. Intraoral photograph with
the contralateral palatal island flap sutured into position and relining the
oral cavity defect.
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Figure 5. Case 1. Postoperative photograph
at 4 weeks demonstrating the new mucosa donor site and the reconstruction
of the palatal-retromolar trigone defect.
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Case 2
This patient was a 61-year-old man with complaints of persistent oral
pain at the site of a recent dental extraction who was referred to Mount Sinai
Medical Center by a local dentist. Physical examination revealed a right-sided
2 x 1-cm soft palate mass with extension onto the superior margin of
the ipsilateral tonsil. A biopsy specimen of the lesion revealed well-differentiated
squamous cell carcinoma (T1 N0 M0). The lesion was excised in combination
with an ipsilateral selective neck dissection. The intraoral defect measured
3.0 x 2.5 cm. A right-sided palatal island flap was raised and used
to resurface the intraoral defect. Postoperatively, the patient began a clear
liquid diet on day 1 and advanced to a regular diet by postoperative day 5.
Epithelialization of the palatal donor site defect was complete by postoperative
week 4 (Figure 6). Currently, the
patient tolerates a regular diet with no velopharyngeal insufficiency or discomfort
at the donor site.
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Figure 6. Case 2. Postoperative photograph
of intraoral reconstruction at 4 weeks. The donor site defect has completely
become resurfaced with new mucosa, and the patient is able to function without
the necessity of an oral obturator.
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COMMENT
Oral cavity reconstruction has evolved during the past several decades
so that there is now a wide variety of techniques that are available to the
head and neck surgeon. It is no longer necessary to create secondary aesthetic
deformities such as those that occurred with the transfer of a forehead flap
into the oral cavity. It is also not necessary to create a secondary functional
deformity by borrowing portions of the tongue to resurface adjacent areas
of the mouth. However, although microvascular surgery has expanded the range
of available tissue, the goal of restorative surgery should be to use the
simplest technique that causes the least amount of secondary morbidity and
provides the optimal level of form and function to the reconstructed area.
Local flaps are always preferable to more complex techniques, provided that
the principles outlined herein are adhered to.
There are a wide variety of local flaps of the oral cavity that have
been described. The palatal island flap is unique for the following reasons.
It transfers a large area of tissue, which is well vascularized and sensate.
In addition, there is very little donor site morbidity due to the very unique
features of the donor site defect that overlies the hard palate. The "remucosalization"
of the hard palate results in very little to no contracture and creates a
near normal-appearing hard palate surface. The mucoperiosteal palatal island
flap is easily harvested and provides a 1-stage reconstruction of suitable
adjacent defects. In 1977, Gullane and Arena5
introduced this flap for the restoration of postablative defects. They reported
a 95% success rate in a series of 53 cases. In addition, they discovered that
up to 90% of the palatal mucosa could be harvested based on a single vascular
pedicle. Anatomic studies by Maher9-10
supported the ability to transfer a subtotal palatal flap based on 1 greater
palatine vascular pedicle. The "macronet" of submucosal vessels identified
by Maher formed the anatomic basis for transfer of the entire palatal island
flap. Another anatomic feature of the vascular supply of the palate makes
it unique among reconstructive techniques. The greater palatine neurovascular
pedicle runs through its bony canal to emerge from the greater palatine foramen.
Mobilization of the palatal island flap is therefore limited by this anatomic
feature, which restricts its use to posterior palatal defects and adjacent
mucosal defects of the lateral pharynx and retromolar trigone.
Mucosal defects of the hard palate do not require any form of reconstruction
and can be permitted to heal by secondary intention. Defects that extend through
the bone but do not violate the underlying antral or nasal mucosa likewise
do not require reconstructive surgery. However, defects that extend through
the nasal and/or maxillary cavities will require either a prosthesis or reconstructive
surgery. Although prosthetic restoration often provides a very suitable functional
result, this selection requires that the prosthesis be worn to prevent oronasal
regurgitation and abnormal resonance qualities. Closure of such defects avoids
this inconvenience for the patient and permits the patient to function in
an unencumbered fashion. As demonstrated in this series, the use of the palatal
island flap provides a superb reconstructive tool for select posterior palatal
defects that are of suitable size that the residual palate can be mobilized
to provide a complete closure. Basic reconstructive principles would suggest
that a 2-layer closure was required, with an inner layer used to reline the
oronasal defect and the second layer to resurface the palate. However, the
very tough mucoperiosteal tissue of the palatal island flap provides an excellent
composite flap that successfully restored all of the oral-nasal defects presented
in this series. The surgeon must make a critical appraisal of the size of
the defect and the amount of residual palate available for transfer to determine
if an alternative technique is more suitable.
Limited defects of the lateral pharynx can also be allowed to heal by
secondary intention, with the tonsillectomy defect being a prime example of
this strategy.
However, this approach is not suitable if the defect communicates with
the neck or the tissues have been previously irradiated. Defects of the retromolar
trigone are less suitable for healing by secondary intention because of the
impact of scarring in this region, which produces limitations in the oral
aperture. Trismus due to scarring in the retromolar trigone can be difficult
to correct but readily avoided by resurfacing with thin pliable tissue such
as the palatal island flap. To achieve an adequate arc of rotation to reach
these defects, the flap must be based on the ipsilateral greater palatine
pedicle.
Contraindications to the use of this flap include age younger than 5
years. Before this age the maxilla has not adequately matured. Disruption
of the overlying periosteum was found to cause midface growth restriction
and subsequent malocclusion.7 A second contraindication
is a history of possible disruption to the vascular pedicle, ie, previous
palatal surgery, irradiation, and internal maxillary or external carotid ligation.
Although reconstructive surgery of the oral cavity has made significant
advances, it is imperative that older, established techniques not be forgotten.
The palatal island flap is a technique that has proven to be very valuable
for the indications presented in this series. Despite the paucity of published
reports using this flap since its description in 1977,5
it remains a valuable reconstructive tool that should be selected as a first-line
option for similar defects to those presented in this series.
AUTHOR INFORMATION
Accepted for publication January 18, 2001.
Presented at the annual meeting of the Head and Neck Society, Fifth
International Conference on Head and Neck Cancer, San Francisco, Calif, August
1, 2000.
Corresponding author: Eric M. Genden, MD, Department of Otolaryngology–Head
and Neck Surgery, The Mount Sinai School of Medicine, Box 1189, One Gustave
L. Levy Place, New York, NY 10029.
From the Department of Otolaryngology–Head and Neck Surgery,
Mount Sinai Medical Center, New York, NY.
REFERENCES
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3. Killey HC. The surgical treatment of oro-antral fistula: a report on 362 cases
of oro-antral fistula treated by the buccal flap operation. Minerva Stomatol. 1971;20:166-168.
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4. Bradley P, Brockbank J. The temporalis muscle flap in oral reconstruction: a cadaveric, animal
and clinical study. J Maxillofac Surg. 1981;9:139-145.
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6. Hatoko M, Harashina T, Inoue T, Tanaka I, Imai K. Reconstruction of palate with radial forearm flap: a report of 3 cases. Br J Plast Surg. 1990;43:350-354.
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7. Millard D. Wide and or short cleft palate. Plast Reconstruct Surg. 1962;29:40.
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8. Gullane PJ, Arena S. Extended palatal island mucoperiosteal flap. Arch Otolaryngol. 1985;111:330-332.
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9. Maher WP. Distribution of palatal and other arteries in cleft and non-cleft human
palates. Cleft Palate J. 1977;14:1-12.
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10. Maher WP, Sether LA. Distribution of palatal blood and lymph vessels. In: Bosma JF, Showacre J, ed. Development of Upper
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