Subaponeurotic connective tissue: a safe way to reconstruct facial and oropharyngeal defects

Journal of Cranio-MaxillofacialSurgery (1996) 24, 276-280 © 1996 European Association for Cranio-Maxillofacial Surgery

Subaponeurotic connective tissue: a safe way to reconstruct facial and oropharyngeal defects Jovan Ristid t, Srdja Dedi61, Ljiljana Somer 2, Asen D~olev t, Aleksandar Kiralj 1

1Maxillofacial Surgery Clinic (Head." Prof J. Ristid, DMD, PhD), ZInstitute of Pathology and Histology (Head." Prim G. Bogdanovid, MD), University Hospital, Novi Sad, Yugoslavia

SUMMAR Y The reconstructive technique of using subaponeurotic connective tissue as a pedicle or free flap for large facial and oropharyngeal defects has been developed on the basis of cadaver research and clinical practice. The technique was applied in 33 cases. Anatomico-histological properties of the flap tissue, postoperative results, basic indications for use and comparative advantages of the flap are surveyed in the article. The safety and simple design of the flap is emphasized.

INTRODUCTION

The surface of the tissue was found to be uniform and no variations in consistency were encountered. The thickness varied insignificantly. The extent of the tissue allows harvesting of a sufficient surface area for covering even the largest defects. The most suitable site found for harvesting the flap was the temporal region, including the surface 2 cm above the cranial attachment of temporal muscle.

Contemporary surgical techniques, used in reconstruction of large facial and oropharyngeal defects created during ablation of malignant tumours, have certain disadvantages: myocutaneous arterial flaps (free or pedicled) are bulky, and skin (often hairy), is transposed to a non-physiological environment, while aesthetic defects at the donor site are apparent. Jejunal microvascular flap harvesting can cause serious complications, while the reliability of the method is compromised by a certain percentage of failures due to disordered blood circulation. In a search for a simply accessed, safe flap without the disadvantages of the above mentioned most frequently used flaps, we came to the idea of utilizing the subaponeurotic connective tissue.

Histological findings Histological examinations were performed on sections stained by Haematoxylin-Eosin (HE), Mallory's method and silver impregnation. Subaponeurotic connective tissue was found to be formed predominantly of mucous connective tissue consisting mainly of amorphous intercellular substance (Fig. 1). On fresh tissue cuts, the amorphous part of the intercellular substance is a homogenous gel. Cellular forms are represented only by fibroblasts and fibrocytes, which synthesize the gel and collagen fibres. The presence of other cellular elements was not noted. Irregular fragments and bundles of Mallory-positive collagen type II fibres are also seen (Fig. 2), as well as delicate argyrophylic reticulin fibres--collagen type III (Fig. 3). The tissue is richly vascularized and this fact has also been supported by Tolhurst et al. (1991) and Tremolada et al. (1994) in their studies of the surgical anatomy of the scalp, as well as Fukuta et al. (1994) in their investigation of the blood supply of the galeal frontalis flap. Only in a narrow region around blood vessels is another type of connective tissue present-dense, unformed connective tissue with nonfasciculated collagen fibres prevailing over amorphous intercellular substance (Fig. 4). This finding correlates with the research of Kirolles et al. (1992), who described bilaminarity of the tissue, with an outer vascular layer and an inner avascular, membranous

METHODS Anatomical research 'Scalp is composed of five layers: skin, subcutaneous tissue, epicranium with its aponeurosis, subaponeurotic connective tissue ('Merkel's space' by French authors) and pericranium. Practically, it is better to consider the first three layers as a single layer, because these three stick firmly together in cases of accidental tearing or surgical section of the scalp. Subaponeurotic connective tissue, the fourth layer, is loose and flaccid and enables free movements of the more superficial layers, especially the scalp skin' (Gray, 1980). ToIhurst et al. (1991) use the term 'subgaleal fascia' (SGF) to describe the same layer. Anatomy, morphology and physical properties of the subaponeurotic connective tissue have been studied on 16 fresh cadavers of middle-aged humans with no signs of scalp injury or disease. 276

Subaponeurotic connectivetissue

Fig. 1 - Mucous subaponeuroticconnectivetissue(HE × 400).

Fig. 2 - Bundlesof rough collagenfibresin amorphous intercellularsubstance(Mallory x 400).

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Fig. 4 - Bundlesof collagenfibresin amorphousintercellular matrix and blood vesselswith accompanyingdenseconnective tissue (Mallory x 400). nective tissue could be utilized clinically in the form of a pedicled, or even free flap for reconstruction of intraoperative defects of the oral cavity and face. At the time of the onset of the clinical use of the flap (1987) we were not able to find this operative technique described in the medical literature. Much later, Tolhurst et al. (1991) considered the flap 'useful for facial reconstruction'. Faivre and Faivre (1992) describe the technique of deep temporal facelift where they use 'the dissectable space described by Rouviere between the galea and temporalis muscle' as a plane for 'hydrodissection'. The flap was applied in 33 cases for restoration of facial skin defects (Fig. 5), mubosal defects of the tonsillar and oropharyngeal region (Fig. 6), defects of buccal mucosa, defects of the soft palate, covering of denuded bony surfaces of the maxilla and for restoration of the roof of the orbit and inner plate of the frontal bone (Fig. 7) (Table 1). Restored intraoperative defects were created by different types of tumour (Table 2).

RESULTS

Irregularlydisperseddelicatereticulinfibresin amorphous intercellularsubstance(Silverimpregnation x 400).

Fig. 3 -

layer. Tolhurst et al. (1991) speak of trilaminar structure of the tissue, which could not be supported by our findings. Clinical research

On the basis of the cadaver anatomico-histological research, it was concluded that subaponeurotic con-

The flap was applied with complete success in the wide majority of cases. Minor complications in terms of partial flap necrosis were rare (Table 3). Partial necrosis of the flap resulted from separation of the flap from the denuded bony surfaces of the maxilla due to haematoma (2 cases). In the third case, partial necrosis of the flap placed in a tonsillar defect occurred because of intensive postoperative coughing.

DISCUSSION On the basis of cadaver anatomical-histological research, several conclusions were drawn. Sub-

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Journalof Cranio-MaxillofacialSurgery Table 3 -

Flap application results

Result

Number of cases

Percentageof cases

Completely successful Complications (partial necrosis)

30 3

90.9 9.1

the mucous tissue represent a mature cell form, there is no possibility of differentiation into other cell types. Due to the high percentage of hyaluronic acid, mucous substance gives the subaponeurotic connective tissue a good turgor (the same quality of tissue is found in the umbilical cord, which prevents kinking of umbilical blood vessels). The rich capillary network in the tissue makes a good cover or base for other types of tissue. Impregnation of the tissue by graft or base cells is undisturbed due to the predominance of intercellular substance over the scarce cellular elements. The tissue completely disappears and is substituted by the tissue of the graft or base. After initial experience with 33 cases in clinical use, the pedicle or free subaponeurotic connective tissue flap has the following basic indications for use:

Basal cellcarcinomaof nasal skin. (B) Region of defect 1 year postoperatively(freeflap applied).

Fig. 5 (A) -

Table 1 - Site of intraoperativedefect restored by the flap Site of defect

Number of cases

Facial skin Tonsillar and oropharyngealmucosa Buccal mucosa Soft palate mucosa Maxilla - - denuded bony surface Orbital roof and frontal bone (int. plate) Total

13 14 2 1 2 1 33

Table

• Covering of oropharyngeal mucosal defects • Reconstruction of particular facial skin defects • Covering of denuded surfaces of the maxilla secondary to resection • Lining for all types of flaps (raw surfaces) • Covering of bony surfaces (as a base for splitthickness skin graft). As far as the operative procedure is concerned, it is of extreme importance that the whole surface of the flap is closely applied to its base, as is necessary in placing a Thiersch graft. This is achieved by exact haemostasis and by placing several sutures through the flap and its base.

CONCLUSIONS

2 - Type of tumour ablated

Tumour

Number of cases

Squamous cell carcinoma Basal cell carcinoma Transitional cell carcinoma

25 6 2

aponeurotic connective tissue is immunologically inactive, because it does not contain the cells necessary for an immune reaction--lymphocytes, plasmocytes, histiocytes, mastocytes. As fibroblasts in

On the basis of experience gained we emphasize the multiple advantages of the subaponeurotic tissue flap. It is not bulky and has extremely good adaptability and resistance to infection. Restitution of mucosa occurs with no major scars. The flap proved to have a high level of safety, simple design, absence of functional or aesthetic inconveniences at the donor site and a wide range of indications for use. The flap most certainly has the ability to restore large intraoperative defects.

Subaponeurotic connective tissue

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Fig. 6(A) - Squamous cell carcinoma of pterygomandibular and tonsillar region. (B) Intraoperative view after tumour ablation and radical neck dissection. (C) Subaponeurotic connective tissue flap raised. (D) Appearance of defect 1 week postoperatively (the flap tunnelled to the site).

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Journal of Cranio-Maxillofacial Surgery

Fig. 7(A) -Transitional cell carcinoma of the frontal sinus with destruction of int. table of frontal bone and roof of the left orbit (exophthalmos visible). (B) Sagittal MR scan. (C) Subaponeurotic connective tissue flap raised from frontal and part of parietal region and placed into the defect. (D) Appearance of the patient 1 week postoperatively. References Faivre, Y., J. M. Faivre: Role of deep temporal lift in the surgical treatment of face aging. Ann. Chir. Plast. Esthet. 37 (1992) 53-66 Fukuta, K , Z. Potpari~, T. Suginara, A. Rachmiel, R. A. Forte, I. T. Jackson." A cadaver investigation of the blood supply of the galeal frontalis flap. Plast. Reconstr. Surg. 94 (1994) 794-800 Gray's Anatomy, 36th Edition. Churchill Livingstone, Edinburgh, 1980 Kirolles, S., F. A. Haikal, F. A. Sadeh, H. Abdul-Hasan, A. R. el-Bakaury: Fascial layers of the scalp. A study of 48 cadaveric dissections. Surg. Radiol. Anatomy 14 (1992) 331333 Tolhurst, D. E., M. H. Carstens, R. J. Greco, D. J. Hurwitz: The

surgical anatomy of the scalp. Plast. Reconstr. Surgery 87 (1991) 603-612 Tremolada, C., P. Candiani, M. Signorini, M. Vigano, L. Donati: The surgical anatomy of the subcutaneous fascial system of the scalp. Ann. Plast. Surg. 32 (1994) 8-14 Prof. Dr. Jovan Risti~ Maxillofacial Surgery Clinic 21000 Novi Sad Hajduk Veljkova 7-9 Yugoslavia Phone: 381 212 5360 fax: 381 212 9929 Paper received January 15 1996 Accepted July 15 1996