CASO CLÍNICO

 

Scapular osteocutaneous free flap in the deferred treatment of firearm wounds

Colgajo libre osteocutáneo escapular en el tratamiento diferido de herida por arma de fuego

 

 

D. Durán Moreno¹, A. Cabello Serrano², A.B. Marín Fernández², C. Bailon Berrio², J.A. Rodríguez Ruiz^1,3

1 Médico Adjunto.
2 Médico Residente.
3 Medico Adjunto del H.U. Puerta del Mar de Cádiz.
Servicio de Cirugía Oral y Maxilofacial.
H.U. Virgen de las Nieves. Granada. España.

Dirección para correspondencia

 

 

---

ABSTRACT

Firearm wounds caused by high-velocity projectiles cause enormous losses of bone and soft tissue. The deferred treatment of these cases (delayed reconstruction) in most cases requires the transfer of free tissue from other areas of the body. The use of scapular and parascapular free flaps with scapular bone for the reconstruction of large lateral mandibular defects with extensive soft-tissue avulsion is reported. The technical details of a free flap are offered with illustrations in the case report of a 19-year-old male who was shot at close range in the lower third of the left lateral face. Avulsion of the left mandibular body and soft tissue occurred in the region from the cheek to the oral commissure. The initial treatment was tracheostomy, cleaning of necrotic and devitalized tissues, wiring of a mandible-to-maxilla arch bar and intermaxillary fixation, rigid fixation with a reconstructive mandibular plate, and a regional cervical flap to close the skin wound. The cervical flap was lost and a postoperative oral-cervical fistula appeared. Scar contraction limited the mouth opening to 0.8 cm. In deferred treatment, a scapular and parascapular free flap with scapular bone from the left shoulder was used to reconstruct the mandibular and intraoral-facial soft-tissue defects. The aesthetic and functional results were optimal. Some complications occurred: postoperative salivary fistula, deinsertion of the long head of the brachial triceps, and scapular wound dehiscence, which will be closed surgically with a local flap.

Key words: Firearm wounds; Mandibular reconstruction; Scapular free flap.

---

RESUMEN

Las heridas por arma de fuego de velocidad alta o intermedia, provocan importantes pérdidas de tejido óseo y blando. El tratamiento diferido de estos casos (tratamiento reconstructivo) requiere el aporte de tejido sano de regiones distantes mediante técnicas microquirúrgicas en la mayoría de las ocasiones. Exponemos la utilidad del colgajo osteocutáneo escapular (COE) para la reconstrucción de defectos óseos mandibulares laterales con amplio defecto cutáneomucoso. Citamos detalles técnicos de la realización del colgajo ilustrados con la presentación de un caso clínico de un varón de 19 años con herida por arma de fuego en tercio inferior de la región lateral izquierda. Pérdida ósea del cuerpo mandibular y cutánea de la mejilla y región yugal ipsilateral.
El tratamiento inicial consistió en traqueotomía, desbridamiento de tejidos desvitalizados, ferulización dentaria, bloqueo intermaxilar, colocación de placa de reconstrucción mandibular y colgajo de avance cervico-facial para cierre del defecto cutáneo. La necrosis del colgajo de avance cervicofacial produjo comunicación orofacial. La retracción cicatricial limitó la apertura oral a 0,8 cm. De forma diferida se procedió a colgajo osteomiocutáneo escapular-paraescapular del brazo izquierdo para reconstrución mandibular y de partes blandas intra y extraorales. Resultados satisfactorios estética y funcionalmente. Complicaciones producidas: fístula salival, desinserción del brazo largo del tríceps, y dehiscencia de herida de zona donante escapular que necesitó intervención para cierre mediante colgajo local.

Palabras clave: Herida por arma de fuego; Reconstrucción mandibular; Colgajo osteocutáneo escapular.

---

 

Introduction

Firearm injuries are uncommon in our country. These wounds can be classified according to the speed of the projectile: wounds produced by high-speed projectiles (military long barrel firearms, with a projectile speed of more than 300 m/s), wounds produced by shot (hunting shotguns) with an intermediate projectile speed, and wounds produced by low-speed projectiles (pistols and revolvers, with a speed of less than 300 m/s).

It was traditionally thought that the potential for damage of the projectile was determined by its mass and speed, which determined the kinetic energy of the projectile. However, other parameters condition bodily damage, such as the internal ballistics (trajectory of the projectile in the weapon), external ballistics (trajectory after leaving the weapon), and terminal ballistics (which studies the transmission of energy to tissues).¹

In general, low-speed projectiles produce injuries with little bone and soft tissue loss. The associated injuries are confined to the trajectory of the projectile.

The firing of shotguns and high-speed projectiles produces abundant loss of soft tissue and bone, originating serious anatomic disruptions and copious bleeding. Airway tract involvement is frequent.²

In our environment, wounds caused by shotguns are the most common firearm injuries, particularly cases of attempted suicide.¹

Two phases can be distinguished in the treatment of firearm injuries:

1. Initial treatment

The objective is to keep the airway open (intubation, cricothyroidotomy, tracheotomy), control hemorrhage (ligation of bleeding vessels), prevent hypovolemic shock, and perform conservative debridement (removal of devitalized bone and soft tissue) (Fig.1).

In this phase, fractures are treated by reduction and fixation adapted to the injury (Fig.2). In the frequent cases of loss of bone substance, the defect can be "bridged" with a reconstruction plate and locking screws.

Primary closure of the cutaneous or mucosal defect must be a secondary objective, particularly in cases of major tissue defects (pending secondary treatment).

2. Deferred, reconstructive, or secondary treatment

This is done 15 to 25 days after the initial treatment in cases that require tissue in the form of microvascularized free flaps. The longer it takes to carry out this treatment, the greater the difficulties will be due to soft tissue retraction and cervical lymph node inflammation, especially in young patients, which makes it difficult to prepare the vessels to which the free flap will be anastomosed.

When the bone defect produced by firearm wounds is accompanied by a large soft tissue defect with considerable orofacial or orocervical openings, the scapular osteocutaneous flap makes for effective deferred or reconstructive treatment. It provides bone of suitable length for the majority of defects (up to 15 cm), with an adequate thickness for a later implant-supported rehabilitation, especially in young muscular subjects. It also supplies sufficient skin and subcutaneous tissue for intraoral mucosal and cervical cutaneous reconstruction.

After reviewing the scapular osteocutaneous flap technique (which has been described in detail by many authors),^3,4 a clinical case is presented with discussion of the usefulness of this donor area in the deferred treatment of firearm wounds with abundant loss of substance.

 

Scapular osteocutaneous flap: technical details

The scapular-parascapular osteocutaneous free flap (SOF) occupies an important place in the microsurgical reconstruction of complex mixed cutaneous-mucosal-bony defects of the head and neck. The flap is based on the arterial axis consisting of the axillary artery, subscapular artery, scapular circumflex artery, and scapular-parascapular arteries.

These complex defects are found in injuries produced by firearms such as shotguns (hunting) and high-speed projectiles.

Once the decision is made to perform SOF, the flap generally is drawn the day before surgery on the patient, who is in standing position, with the torso bare and the arms hanging. (Fig.3). The scapula on the side opposite the defect usually is used. The omotricipital triangle is located at the point where a line drawn horizontally from the highest part of the posterior axillary fold to the lateral edge of the scapula. Doppler ultrasonography can help to locate the arterial branches to be preserved.

On the day of the intervention, after the donor vessels (superior thyroid, lingual, or facial arteries) are dissected, the patient is placed in lateral prone position with the arm flexed 90º, perpendicular to the chest. It is useful to use an arm support and to tape the hip to the table in the proper position. The flap is raised from the distal point with the thoracolumbar fascia that covers the latissimus dorsi, teres major, teres minor, and trapezius muscles. The fascia of the infraspinatus and deltoid muscles is excluded. In the omotricipital triangle, the fascias are separated to probe deeper in the omotricipital space, which is limited by the teres minor fascia above and teres major fascia below. Laterally it is limited by the long head of the triceps brachii muscle. The lateral crest of the scapula is a landmark because the pedicle emerges immediately adjacent to it. We enter the loose areolar plane to section the direct vascular branches to the teres major muscle.

Near the lateral crest, our next actions depend on the type of flap being prepared:

1. Skin flap without bone (scapular-parascapular). We section the following branches of the scapular

2. circumflex artery (SCA):

• Pedicle of the bone nutrient artery.

• Descending branch.

• Branch of the infraspinatus.

• Anterior scapular circumflex branch for the subscapularis muscle.

3. Osteocutaneous flap. The following branches of the SCA are conserved:

• Pedicle of the bone nutrient artery.

• Descending branch.

The following arteries are sectioned:

1. Branch of the infraspinatus artery.

2. Anterior scapular circumflex branch for the subscapularis muscle.

An osteotomy is made below the insertion of the triceps brachii muscle, leaving a muscular rim of the insertion of the teres minor, teres major, or subscapularis muscle. There may be bleeding from the anterior branch of the SCA to the subscapularis muscle. As noted above, we leave the bone nutrient artery and descending branch of the SCA. Probing inwards we find the thoracodorsal vessels and the convergence of the SCA with these vessels, which together form the subscapular vessels.

It is important to preserve the dorsal cutaneous nerve.

When we reached this point we chose the point of dissection of the SCA pedicle, separating the artery and vein for ligation. A venous bridge crosses the SCA and joins the two veins of the pedicle, which should not be damaged.

The artery is ligated first and then the vein is ligated. The SCA-subscapularis artery "axis" is ligated at two points:

1. On the SCA, before the bifurcation of the thoracodorsal artery (as seen from the surgeon’s perspective). This results in a pedicle 7-10 cm long by 2.5-3 mm diameter.

2. Ligation of the trunk of the subscapularis artery. The thoracodorsal artery is ligated and we continue inward along the subscapularis artery to its convergence with the axillary artery. This results in a pedicle up to 11-14 cm long by 3-4 mm diameter.

The donor zone is closed directly and the arm on the operated side is supported in a sling for two weeks followed by rehabilitation.

 

Clinical case

A 19-year-old male was admitted from the emergency department with a firearm wound (shotgun) after trying to commit suicide (impact distance less than one meter). He presented a wound of the lateral lower third of the face with major bone loss from the left first premolar to the left mandibular angle. He had a large cutaneo-mucosal defect in the left jugal and cheek region. The initial actions were tracheotomy, debridement of devitalized tissues, dental splinting, maxillomandibular fixation, and placement of a mandibular reconstruction plate(Figs. 1 y 2).

In this first surgical stage, direct intraoral closure and skin closure with a cervicofacial advancement flap were performed.

In the immediate postoperative period, the cervicofacial advancement flap suffered and was lost, leaving a large area of facial granulation tissue on the left side. Scar retraction of the oral mucosa tissue restricted mouth opening (0.8 cm). Orofacial openings and salivary fistulas appeared.

A secondary intervention was decided on, which consisted in a scapular-parascapular osteomyocutaneous flap from the nondominant left arm because the patient had a history or recurrent shoulder dislocation.

The intervention began with a new tracheotomy and the preparation of the receptor vessels: the facial artery and branch of the thyrolinguofacial venous trunk. A large amount of level I and III cellular lymphatic tissue had to be excised in order to dissect the receptor vessels.

The scapular-parascapular osteocutaneous flap then was dissected and the donor zone was closed. Aspiration drainage was left in place and the left arm was immobilized in a sling (Figs.3 y 4).

Next, the bony part of flap was adapted to the mandibular defect with its osteosynthesis using the reconstruction plate inserted in the initial intervention (Fig. 5). The cutaneous part of the flap was folded like a book, leaving one of the cutaneous lobes inside the mouth and the other outside the mouth (facio-cervical). The epithelium was removed from dorsal part of the "book," which was sutured to the residual lower lip (Fig. 6). The intraoral part was used to reconstruct the entire jugal mucosa to the anterior pillar of the soft palate. The external part was used to reconstruct the left cutaneous mandibular and submandibular area. The posterosuperior region of the cutaneous defect was for the dermoepidermal graft. The maxillomandibular fixation and dental splint were removed and the mouth was left "open."

The flap adaptation required submaxillectomy and excision of part of the subcutaneous tissue of the posteroinferior area.

The scapular circumflex artery was anastomosed endto- end to the facial artery. The largest of the circumflex veins was anastomosed to the thyrolinguofacial trunk.

The duration of the intervention was 14 hours, with an ischemia time of 2.45 hours.

The evolution was satisfactory in terms of the vitality of the scapular flap. Local complications: posterosuperior parotid-salivary fistula due to loss of the dermoepidermal graft on the masseteric region (Figs. 7 y 8).

Donor zone complication: deinsertion of the triceps long head and wound dehiscence. This dehiscence was treated surgically with a local transposition flap (Figs. 9 y 10). Postural complication: contralateral (right) paralysis of the radial nerve.

The patient is undergoing rehabilitation to recover leftarm mobility.

 

Discussion

Generally speaking, the objectives of the treatment of firearm wounds in the facial region are:

1. To conserve the patency and functionality of the aerodigestive tract (naso-oral).

a. Good mouth opening (4-5 cm), functional orbicularis oris muscle.

b. Independent and anatomically correct nasal cavity.

c. Prevention of orocervical or orocutaneous fistulas.

d. Swallowing function.

2. Preservation of sensory organs: aesthetically and functionally.

3. Separate the aerodigestive space from the cranial cavity.

4. Bone reconstruction.

a. Mandible. Important for chewing function and projection of the lower third.

b. Maxilla and middle third of the facial massif. Important for chewing function and the aesthetically acceptable appearance of the middle third of the face.

c. Frontal. Fundamentally of aesthetic importance.

5. Aesthetically acceptable skin and mucosal coverage, avoiding bone exposure.

6. Implant-supported dental rehabilitation (not always indicated).

In wounds caused by low-speed projectiles in which the loss of substance is not important,⁵ definitive primary treatment can generally be provided by osteosynthesis of the fractures and closure directly or with local flaps.

In high-speed firearm or shotgun wounds, large tissue losses are common, which requires careful evaluation and secondary treatment, especially in the region of the lower third and side of the face. Although there are magnificent review articles on mandibular reconstruction (6), we briefly review the reconstructive possibilities for soft tissues and bone below.

Soft tissues can be treated by directly closure of the wound or the use of local flaps (lingual, nasogenial, buccinator), regional flaps (pectoralis major, trapezius, sternocleidomastoideus, platysma), or free flaps (antebrachial, lateral brachial, lateral thigh, or other).

The following strategies can be used for the surgical treatment of mandibular bone defects: no reconstruction or reconstruction using a plate, autologous free graft,^6,7 allogeneous mandible (cryopreserved), segmental mandibular distraction, regional flaps (lateral trapezial osteomyocutaneous)⁸, and free flaps: fibula,⁹ iliac crest,¹⁰ scapula,^3,4 radius.¹¹

Microsurgical techniques are now superior to traditional methods for reconstructing the region of the head and neck in general and in the lower third of the face in particular.

Microvascularized flaps based on the subscapularis axis can replace most free flaps in the reconstruction of the face.

The following types of flaps can be shaped:

1. Soft tissue flaps: scapular, parascapular, serratus, or latissimus dorsi flaps; musculocutaneous flaps.

2. Bone flaps: scapular parascapular osteocutaneous flap, osteomyocutaneous flap (scapular-parascapular-osteolatissimus dorsi-serratus, also called "megaflap"), bone flap.

The scapular flap has the following advantages as an osteocutaneous flap:

1. It provides abundant soft tissues, three-dimensional plasticity, bone length adequate for most defects, and a long pedicle of good caliber, particularly when it includes the subscapular artery.

2. The scapular skin is hairless and can be folded easily in thin or elderly people.

3. As noted, the amount of bone is sufficient, up to 14 cm, and can be expanded up to 18 cm by including in the flap the angular artery, branch of the dorsal cutaneous artery, and the tip of the scapula.

The main disadvantage is the practical impossibility for two teams to work simultaneously. This prolongs the operation and also requires two changes in patient posture and the preparation of new operating fields. The intervention is more expensive, as already has been mentioned.¹²

The flap usually is taken from the side opposite the defect because it is easier to approximate the vascular pedicle to the receptor vessels by orienting the edge of the scapula downwards. However, in this patient the flap was obtained from the same side as the injury due to a history of shoulder dislocation. This forced us to invert the position of the bone flap in the reconstruction of the mandible. This did not affect the adaptation of the soft tissues or their viability, nor do we believe that it will interfere with the implant-supported dental rehabilitation when the time comes.

The bone adaptation of the flap to the locking-screwaffixed reconstruction plate was important, but even more important was the adaptation of the soft tissues, which required a great deal of experience and actions such as defatting the graft or same-side submaxillectomy, as in this case.

In our experience (Cádiz-Granada and a total of 15 patients), flaps of the subscapular axis were used as donor areas for mandibular reconstruction when the first options were impossible (fibula, iliac crest) or the defects included total thickness soft tissues above the commissure.¹³ The good results obtained (2/15 flap losses: 13.3%) outweighed the disadvantages, which is why we think that this intervention should be considered as first choice in mandibular reconstruction with large cutaneous-mucosal defects, particularly lateral, eg, firearm wounds. This opinion has been stated in other studies.¹⁴

Mandibular osteogenic distraction^{15, 16} and osseous morphogenetic proteins (currently in the experimentation phase)¹⁷ could be an alternative to microsurgery in the future for benign traumatic defects, such as the case reported here, or neoplasms that have not been irradiated, as long as a supply of soft tissue is not required for the three-dimensional reconstruction of complex defects like our case.

 

Acknowledgments

We thank Rosendo Mangas for correcting the original manuscript.

 

 

Dirección para correspondencia:
Juan Andrés Rodríguez Ruiz
Carretera Jaen 72-A, 5-C
18013 Granada, España
E-mail: katifa@telefonica.net

Recibido: 12.6.08
Aceptado: 25.11.08

 

References

1. Sánchez López JD, Martinez Castillo S, García Medina B, Budiño Carbonero S, Fernandez Solís J, Rojo Aliaga J. Heridas Faciales por arma de fuego. Actitud terapéutica. Rev Esp Cirug Oral Maxilofac 1999;21:3:154-64.        [ Links ]

2. Torres Garzón L, Rodríguez Ruiz JA. Traumatología Facial. En: urgencias en Rodríguez Ruiz JA, y cols. Urgencias en Cirugía Oral y Maxilofacial. Servicio de Publicaciones de la Universidad de Cádiz 2003;65-95.        [ Links ]

3. Sánchez Lorenzo J. Llorente JL, Camporro D, y Fueyo A. Colgajo libre escapular- paraescapular. En: Llorente Pendás JL, Suarez Nieto C. Colgajos libres en las recontrucciones de cabeza y cuello. Edit Garsi. 1997;90-98.        [ Links ]

4. Rodríguez Ruiz JA, Rendón Infante I, Torres Garzón L, Modelo Pérez A, Budiño Carbonero S, Fortis Sánchez E. Reconstrucción oral mediante colgajos microvascularizados vasados en la arteria subescapular. Rev Esp Cirug Oral Maxilofac 2001;23:284-93.        [ Links ]

5. Ramos Xavier L, Alves Crespo M, Soares de Oliveira CM, de Freitas Baldez. Tratamiento inicial de heridas por proyectil de arma de fuego. A propósito de un caso. Rev Esp Cir Oral Maxilofac 2008;30:115-20.        [ Links ]

6. Ochandiano S, Navarro-Vila C, López Atalaya FJ, Cuesta M, Verdaguer JM, Barrios JM, Acero J, Salmerón JI. Reconstrucción mandibular: pasado presente y futuro. Rev Esp Cir Oral Maxilofac 2002;24:75-91.        [ Links ]

7. Foster R, Anthony J, Sharma A, Pogrel A. Vasculariced bone flaps versus nonvascularice bone grafts for mandibular reconstrucción: an outcome analysis of primary bony union and endosseous implant success. Head Neck 1999;21:66-71.        [ Links ]

8. Navarro-Vila C, Borja Morant A, Cuesta M, López de Atalaya F, Salmeron JI, Barrios JM. Aesthetic and funcional recontructión with the trapezius osseomyocutaneous flap and dental implants in oral cavity cancer patients. J Craneomaxilofac Surg 1996;24:322-9.        [ Links ]

9. Hidalgo D. Fíbula free flap: a new method of mandible reconstruction. Plast Recontr Surg 1989;84.        [ Links ]

10. Urken ML Buchbinder D, Costantino P, Sinha U, Okay D, Lawson W, Biller H. Oromandibular recontruction using microvascular composite flaps. Report of 210 cases. Arch Otolaryngol Head Neck Surg 1998;124:46-55.        [ Links ]

11. Casado Pérez C. Colgajo libre antebraquial fasciocutáneo y osteofasciocutáneo radial. En: Llorente Pendás JL, Suarez Nieto C. Colgajos libres en las recontrucciones de cabeza y cuello. Edit Garsi 1997;109-17.        [ Links ]

12. Talesnik A, Markowitz B, Calcaterra M Ahn C, Shaw W. Cost and outcome of osteocutaneous free tissue transfer versus pedicled soft tissue reconstruction for composite mandibular defects. Plast Reconst Surg 1996;97:1167-78.        [ Links ]

13. Urken ML Composite free flaps in oromandibular recontructión. Review of the literature. Arch Otolaryngol Head Neck 1991;117:724-32.        [ Links ]

14. Deschler DG, Hayden RE. The optimum method for recontrucción of complex lateral oromandibular-cutaneous defects. Head Neck 2000;22:674-9.        [ Links ]

15. Ilizarov GA. Clinical application of the tensión-stress effect for limb lengthening. Clin Orthop 1990;250:8-26.        [ Links ]

16. Mc Carthy JG, Schreiber J, Karp N y Cols. Lengthening the human mandible by gradual distraction. Plast Reconst Surg 1992;89:1-8.        [ Links ]

17. Boyne PJ. Animal studies of the application of rhBMP-2 in maxillofacial recontruction. Bone 1996:19:83-92.        [ Links ]