Pathologies of oral and sinonasal mucosa following facial vascularized composite allotransplantation

BACKGROUND

Cutaneous changes of facial vascularized composite allotransplants (fVCAs) are extensively described in the literature. Parts of the nose, nasal, and oral cavities are included in most fVCAs. Distinctively, the nose and mouth are lined by mucosa. Little is known about the histopathology and complications of the mucosa involved in fVCA patients.

METHODS

The study constitutes a retrospective cohort study of nine fVCA patients. Medical records were reviewed for information about changes of oral and nasal mucous membranes. Types of mucosal lesions were recorded and analyzed. Uni- and multivariate generalized estimating equation (GEE) models were used to assess the odds of developing mucosal inflammation in the presence of clinico-pathologic variables.

RESULTS

A total of 186 clinical encounters with examination of oral and nasal mucous membranes were included. Membranes were devoid of clinical pathology in 101 instances (53% of all clinical assessments). Ulcerations/erosions (27%), edema (18%), and erythema (14%) were the most common lesions. Oral lesions affected the lips (58%), buccal mucosa (38%), and palate (5%). Sinonasal processes predominantly affected nasal vestibules and septae. In univariate analysis, sirolimus, skin rejection, and skin Banff grade were associated with the presence of an acute inflammatory mucosal lesion (p<0.05). In multivariate analysis, skin Banff grade and sirolimus were independent predictors of mucosal inflammation.

CONCLUSION

Pathologies of fVCA mucous membranes are more common than previously reported. Mucosal assessment plays an important role in the pleomorphic allograft rejection process evaluation rather than diagnosis and treatment based on cutaneous pathology.  A closer look at the pathophysiology of fVCA mucosal rejection and inflammation is warranted.

Distribution of the maxillary artery in the deep regions of the face and the maxilla: Clinical applications

Composite tissue allotransplantation of the face has led to renewed interest in the vascularization of the maxilla. The maxillary artery, which is deep within the tissue and difficult to access, is considered the main artery of the maxilla. The objective of this study was to describe the distribution of the maxillary artery in the deep regions of the face and maxilla. Twenty-four maxillae were studied, of which 20 were injected with latex and four with India ink. The maxillary artery in the pterygopalatine fossa gave rise to the sphenopalatine artery, infraorbital artery, descending palatine artery, and posterior superior alveolar artery in all 24 cases. The posterior superior alveolar artery gave rise to a periosteal branch and an intraosseous branch (in the wall of the maxillary sinus) in 18 cases. The branch passed through part of the wall and the entire wall in eight and ten cases, respectively, and anastomosed at the anterior nasal spine and the infraorbital foramen. The descending palatine artery presented as a single trunk in four cases, a greater palatine artery and a lower palatine artery in 18 cases, and four branches in two cases. Intraosseous and periosteal anastomoses were found along with anastomosis through the incisive foramen, which were obstructed in three cases. The vascular territories were studied. The maxillary artery created an intraosseous and periosteal anastomotic network, explaining the supply pathways during different surgical procedures, risk of hemorrhage with orthognathic surgery (Le Fort type I) in a sinus lift for preimplant surgery, and the vascular territories.

A functional periorbital subunit allograft: vascular, anatomic, and technical considerations for future subunit facial transplantation

BACKGROUND

Injury to the face can result in the loss of critical specialized structures (the eyelids, lips, ears and nose). Vascularized composite allotransplantation (VCA) allows the surgeon to replace exactly what has been lost. The success of the clinical face transplants suggests the possibility of transplanting specialized units of the face. In this study we explore the neurovascular anatomy and technical specifics for harvest of a functional composite eyelid subunit flap.

METHODS

12 fresh cadaver heads were studied, each yielding two flaps (N = 24). The facial (FA) and superficial temporal arteries (STA) were cannulated and injected with a gelatin/acrylic dye mixture. 6 cadaver heads were evaluated via high-resolution three-dimensional CT scans with contrast.

RESULTS

The dye injected into the STA uniformly stained the tissue of the eyelid/periorbital subunit. Injection into the FA resulted in staining of the skin and soft tissues in the medial canthal region and superior eyelid skin in 66% of specimens. CT scan studies confirm our findings with injection into the STA resulting in contrast infiltration of the palpebral arterial arcades in all cases. Injection of the FA resulted in contrast infiltration of the palpebral arterial arcades in 2 of 3 cases.

CONCLUSIONS

Based this study, a periorbital flap can be based on the STA. Motor innervation of the flap is via the zygomatic and buccal branches of the facial nerve with sensory innervation via the infraorbital, supraorbital and supratrochlear nerves. FA could be used, but its ability to perfuse the entire flap was inconsistent.