MASTER OF DENTAL SURGERY (M.D.S) ORAL AND MAXILLOFACIAL SURGERY
Date of admission TO THE Course
21st APRIL 2009
Title of the DISSERTATION:
CLINICAL & COLOUR DOPPLER EVALUATION OF THE VASCULAR ANATOMY OF THE ISLAND NASOLABIAL FLAP BASED ON A CENTRAL SUBCUTANEOUS PEDICLE.
BRIEF RESUME OF INTENDED WORK
Need for the study:
An ablative procedure for management of maxillofacial pathologies creates various defects. The reconstructive option with various modifications have been extensively used for reconstructive purposes in the orofacial region.1 The nasolabial flap has been widely employed as a versatile reconstructive option for small to moderate sized defects of the oral & perioral regions. Sushruta Samhita contained a description of the nasolabial flap. During the 1800s, pictures of nasolabial flaps began to appear in print. Contemporary surgical descriptions began in 1830 when Dieffenbach used superiorly based nasolabial flaps to reconstruct nasal alae. In 1864, Von Langenbeck used the nasolabial flap to reconstruct the nose. Fifty-seven years later, Esser described the use of the inferiorly based nasolabial flap to close palatal fistulae. Since these early publications, the nasolabial flap has been described for reconstruction of the floor of the mouth, lips, tongue, buccal mucosa, upper and lower alveolus, maxilla, and oronasal defects.1 The anatomy of the nasolabial region is complex.The nasolabial flap is typically classified as an axial pattern flap given that the angular artery runs deep to the flap. Nevertheless, for applications such as the nose, the flap is thinned and does not contain the artery. The skin of the nasolabial fold has a superior and inferior blood supply allowing for a superiorly or inferiorly based flap. The facial artery is the arterial supply of the inferiorly based flap. The skin of the nasolabial fold is nourished by the superolabial and alar branches of the facial artery. As the facial artery courses over the dorsum of the nose, it becomes the angular artery. These branches form the distal arterial supply of the inferiorly based flap. The infraorbital artery and the transverse facial artery supply the superolateral skin of the nasolabial region and form the basis of the superiorly based nasolabial flap. A study of the vascularization of the cheek has demonstrated that, although the lower three quarters of the nasolabial fold skin has a reliable subcutaneous vascular distribution, the distal third should be considered to have a random distribution.1
The versatility of this flap has been attributed to the fact that there has been abundant non-hair bearing skin in the well vascularised region. The facial & infraorbital arteries are frequently cited in anatomic description of the nasolabial flap. The venous drainage is believed to be via the angular & facial veins.2
The centrally-pedicled nasolabial flap offers outstanding features, providing supple soft-tissue lining & adequate flexibility to the cheek thus facilitating excellent mouth opening on a long term basis. The ease of harvest & negligible aesthetic morbidity makes it a viable option instead of superiorly or inferiorly based nasolabial flap.3 Colour Doppler sonography has been developed to identify vasculatures & to enable evaluation of the blood flow velocity & vessel resistance together with surrounding morphology, it can be applied to the diagnosis of various lesions. Although the facial artery is an important vessel in this area, its Doppler sonographic features are not well known in the anterior face.4Perhaps the greatest advantage of colour flow imaging is technical efficiency. When moving blood is encountered, the vessel “lights up”, even if the vessel is too small to be resolved on the gray-scale image.5 Considerable confusion does exist with regard to the pattern of its blood supply & is generally misconstrued as an axial pattern flap, based on facial artery.3 This study is designed to resolve the dilemma regarding vascular basis for centrally-pedicled nasolabial flap.
Review of literature:
In a study carried on 12 cadaveric specimens & microangiography on 6 others to confirm the random nature of nasolabial flap & they suggested that although the vasculature of the flap is technically random, the small vessels of the subdermal plexus are generally oriented along its long axis giving it a “degree of axiality.”
In a study carried on 40 personal dissections to know the anatomical basis of nasolabial flap to illustrate a musculo-cutaneous nasolabial island flap with a proximal pedicle & they confirmed the interest of proximal of proximal base especially with regard to venous return.6 In another study carried on 15 patients either unilateral or bilateral nasolabial flap was used for reconstruction of moderate-sized oronasal defects. They used it as a random-pattern flap supplied by the subcutaneous vessels.7 In a study on 31 cadavers carried out to study the course of facial artery & the pattern of its branches, they suggested a new axial pattern skin island flap based on a new cutaneous branch of facial artery.8 In a study, 47 patients with oral submucous fibrosis were treated with bilateral extended nasolabial flaps with central pedicle along with coronoidectomy.9 In a Colour Doppler sonography study on 46 healthy volunteers to depict the facial artery & its branches in the anterior face, it was found that it can clearly depict the facial artery & its branches in the anterior face & would be mostly useful in the follow-up examination.4
Objectives of the Study:
To critically evaluate & establish the vascular basis of centrally-pedicled nasolabial flap via Colour Doppler sonography.
7. MATERIALS AND METHODS : 7.1 Source of data
The study group will consist of 10 patients with soft tissue defects if the perinasal, perioral & intraoral regions usually resulting from trauma, tumour resection & precancerous conditions, reporting to the Department of Cranio-Maxillofacial Plastic & Reconstructive Surgery, College of Dental Sciences, Davangere.
Inclusion criteria: ASA Grade I & II patients
Patients with soft tissue defects of the perinasal & perioral regions to be surgically reconstructed with a centrally-pedicled nasolabial flap, under general anesthesia.
Patients with soft tissue defects that cannot be surgically reconstructed with a centrally-pedicled nasolabial flap, under general anesthesia.
Method of collecting data (including sampling procedure if any)
Ten patients with intraoral defects resulting from trauma, precancerous lesions, tumour resection & congenital anomalies will be included in the study. The following study variables will be taken into consideration:
age & sex of the patient
medical back ground
type & site of the defect
its anatomical complexity
Pre-operatively, the study of the vasculature of the patients’s face of the concerned side will be done via Colour Doppler sonography. Post-treatment healing & survival of the nasolabial flap rates will be clinically evaluated.
In all cases, patient review/follow-up will be done at 1st week, 3rd week & 6th week post-operatively.
Does the study require any investigation or intervention to be conducted on patients or other human or animals? If so, please describe briefly.
Yes Colour Doppler sonography
Has ethical clearance been obtained from your institution in case of 7.3
8 . List of References: Schmidt BL, Dierks EJ. The nasolabial flap: Oral Maxillofacial Surg Clin N Am 2003;15:487-95.
Hynes B, Boyd B. The nasolabial flap. Axial or Random? Arch Otolaryngol Head Neck Surg 1988; 114:1389-91.
Tauro DP A unique Melolabial flap in the surgical management of oral submucous fibrosis-“the sea gull flap”- an experience with 85 case: A Clinical study.Int J Oral Maxillofac Surg 2009;38:508.
Zhao Y, Ariji Y, Gotoh M, Kurita K, Natusme N, Ma X etal. A Colour Doppler sonography of the facial artery in the anterior face: A Clinical study. Oral Surg Oral Med Oral Path Oral Radiol Endod 2002;93 195-201.
Zweibel WJ, Pellerito. Introduction to to vascular ultrasonography.5th ed. SAUNDERS (Elsevier) Pennsylvania,U.S.A. 2005.P-79.
Guero S, Bastian D,Lassau, Cuskonyi. Anatomical basis of a new naso-labial island flap. Surg Radiol Anat 1991;13:265-70.
Lazardis N, Zouloumis L, Venetis G, Karkasis D. The inferiorly & superiorly based nasolabial flap for the reconstruction of moderate-sized oronasal defects.J Oral Maxillofac. Surg. 1998;56:1255-9.
Gardetto A, Moriggl B, Maurer H, Erdinger k, Papp C. Anatomical basis for a new island axial pattern flap in the perioral region. Surg Radiol Anat 2002;24:147-54.
Borle RM, Nimonkar PV, Rajan R. Extended nasolabial flapps in the management of oral submucous fibrosis: A .clinical study. Br J Oral Maxillo Surg 2009;47:382-5.