Faculty Bibliography

INTRODUCTION: The anatomy of the facial artery, its tortuosity, and branch patterns are well documented. To date, a reliable method of identifying the facial artery, based on surface landmarks, has not been described. The purpose of this study is to characterize the relationship of the facial artery with several facial topographic landmarks, and to identify a location where the facial artery could predictably be identified. METHODS: Following institutional review board approval, 20 hemifacial dissections on 10 cadaveric heads were performed. Distances from the facial artery to the oral commissure, mandibular angle, lateral canthus, and Manson's point were measured. Distances were measured and confirmed clinically using Doppler examination in 20 hemifaces of 10 healthy volunteers. RESULTS: Manson's point identifies the facial artery with 100% accuracy and precision, within a 3 mm radius in both cadaveric specimens and living human subjects. Cadaveric measurements demonstrated that the facial artery is located 19 mm +/- 5.5 from the oral commissure, 31 mm +/- 6.8 from the mandibular angle, 92 mm +/- 8.0 from the lateral canthus. Doppler examination on healthy volunteers (5 male, 5 female) demonstrated measurements of 18 mm +/- 4.0, 50 mm +/- 6.4, and 79 mm +/- 8.2, respectively. CONCLUSIONS: The identification of the facial artery is critical for the craniofacial surgeon in order to avoid inadvertent injury, plan for local flaps, and in preparation of a recipient vessel for free tissue microvascular reconstruction. Manson's point can aid the surgeon in consistently indentifying the facial artery.

BACKGROUND: Fractures of the mandibular condyle are common following blunt facial trauma and carry an increased risk for concomitant blunt carotid artery injuries (BCAI), a potentially life-threatening complication. Further elucidation of the relationship between specific condylar fracture patterns and BCAI may improve vascular injury screening and management. METHODS: A retrospective cohort study was performed for all craniofacial trauma patients sustaining condylar fractures that presented to a large trauma center from 2000 to 2012. Condylar fracture locations were classified according to the Strasbourg Osteosynthesis Research Group (SORG) system (SORG 1: condylar head, SORG 2: condylar neck, SORG 3: extracapsular condylar base). BCAI severity was based on the Biffl scale. Severe BCAI was defined as a Biffl score greater than I. RESULTS: We identified 605 patients with mandibular condyle fractures consisting of 21.0% (n=127) SORG 1, 26.8% (n=162) SORG 2, and 52.2% (n=316) SORG 3. Overall incidence of BCAI in this population was 5.5%(n=33), of which 75.8 % (n=25) were severe. Severe BCAIs occurred in 1.6% (n=2) of SORG 1, 2.5% (n=4) of SORG 2, and 6.0% (n=19) of SORG 3 fractures (p<0.05). SORG 3 fractures were independently associated with a 2.94-fold increased risk of a severe BCAI compared to other condyle fractures on multivariable analysis (p-value <0.05). CONCLUSIONS: The presence of extracapsular subcondylar fractures should heighten suspicion for concomitant BCAI. Our data additionally support a force transmission mechanism of injury in addition to direct vascular injuries from bony fragments.

PURPOSE: Abdominal compartment syndrome (ACS) is a severe complication of ventral hernia repair. The aims of this study were to investigate the effects of intra-abdominal pressure on the physiologic changes of abdominal wall reconstruction and component separation in a porcine model. METHODS: Ventral hernia repair (VHR) was simulated by abdominal fascial imbrication of a 10 x 15 cm defect in 45 Yorkshire pigs assigned to five experimental groups. ACS was simulated by a Stryker endoscopy insufflator with intra-abdominal pressure elevated to 20 mmHg in two groups. Component separation was performed in one of these groups and in one group without ACS. Physiological parameters were measured before and after the procedures and monitored for 4 h. The animals were euthanized for histologic analysis of organ damage. RESULTS: VHR led to an increase in intra-abdominal pressure, bladder pressure, and central venous pressure by an average of 14.89, 13.93, and 14.69 mmHg (p < 0.001) in all animals. Component separation was performed in 25 animals and the three pressures reduced by 9.11, 8.00, 7.89 mmHg (p < 0.001). ACS correlated with higher percentages of large and small bowel necrosis compared to groups without abdominal compartment syndrome. CONCLUSIONS: The results confirm that primary repair of large abdominal wall defects leads to increased intra-abdominal pressure, which can be reduced with component separation. In animals with ACS, component separation may reduce the risk of organ damage. Central venous pressure, bladder pressure, and other physiologic parameters accurately correlated with elevated intra-abdominal pressure and may have utility as markers for diagnosis of ACS.

BACKGROUND: Composite mandibular tissue loss results in significant functional impairment and cosmetic deformity. This study classifies patterns of mandibular composite tissue loss and describes a microvascular treatment algorithm. METHODS: A retrospective review of microvascular composite mandibular reconstruction from July of 2005 to April of 2013 by the senior surgeon at the R Adams Cowley Shock Trauma Center and at The Johns Hopkins Hospital yielded 24 patients with a mean follow-up of 17.9 months. Causes of composite mandibular defects included tumors, osteoradionecrosis, trauma, infection, and congenital deformity. Patients with composite tissue loss were classified according to missing subunits. RESULTS: A treatment algorithm based on composite mandibular defects and microvascular reconstruction was developed and used to treat 24 patients. A type 1 defect is a unilateral dentoalveolar defect not crossing the midline and not extending into the angle of the mandible. A type 2 defect is a unilateral defect extending beyond the angle. A type 3 defect is a bilateral defect not involving the angles. A type 4 defect is a bilateral defect with extension into at least one angle. Type 2 defects were the predominant group. Patients had microvascular reconstruction using either fibula flaps (n = 19) or iliac crest flaps (n = 5). Complications included infection, partial necrosis, plate fracture, dehiscence, and microvascular thrombosis. CONCLUSION: This novel classification system and treatment algorithm allows for a consistent and reliable method of addressing composite mandibular defects and focuses on recipient vasculature and donor free flap characteristics. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

BACKGROUND: Multiple perfusion assessment technologies exist to identify compromised microvascular free flaps. The effectiveness, operability, and cost of each technology vary. The authors investigated surgeon preference and clinical behavior with several perfusion assessment technologies. METHODS: A questionnaire was sent to members of the American Society for Reconstructive Microsurgery concerning perceptions and frequency of use of several technologies in varied clinical situations. Demographic information was also collected. Adjusted odds ratios were calculated using multinomial logistic regression accounting for clustering of similar practices within institutions/regions. RESULTS: The questionnaire was completed by 157 of 389 participants (40.4 percent response rate). Handheld Doppler was the most commonly preferred free flap-monitoring technology (56.1 percent), followed by implantable Doppler (22.9 percent) and cutaneous tissue oximetry (16.6 percent). Surgeons were significantly more likely to opt for immediate take-back to the operating room when presented with a concerning tissue oximetry readout compared with a concerning handheld Doppler signal (OR, 2.82; p < 0.01), whereas other technologies did not significantly alter postoperative management more than simple handheld Doppler. Clinical decision making did not significantly differ by demographics, training, or practice setup. CONCLUSIONS: Although most surgeons still prefer to use standard handheld Doppler for free flap assessment, respondents were significantly more likely to opt for immediate return to the operating room for a concerning tissue oximetry reading than an abnormal Doppler signal. This suggests that tissue oximetry may have the greatest impact on clinical decision making in the postoperative period.

BACKGROUND: Microvascular reconstruction is the mainstay of treatment in complex scalp defects. The rate of elderly patients requiring scalp reconstruction is increasing, but outcomes in elderly patients are unclear. The purpose of this study was to systematically review the literature pertaining to free tissue transfer for scalp reconstruction in patients older than 65 years to compare outcomes among different free flaps and determine the safety profile of treatment. METHODS: A systematic review of the available literature of patients undergoing microvascular scalp reconstruction was completed. Details for patients 65 years and older were extracted and reviewed for data analysis. RESULTS: A total of 45 articles (112 patients) were included for analysis. Mean age of the patients was 73.3 +/- 6.3 years (men, 69.4 percent; women, 23.4 percent; not reported, 7.2 percent). Mean flap size was 598 cm (range, 81 to 2500 cm). The mean age of patients developing a complication was 72.8 +/- 6.4 years and patients that did not develop a complication was 73.4 +/- 5.5 years (p = 0.684). Overall, periprocedural mortality was 0.9 percent. Flap failures occurred in two cases (1.8 percent). The overall complication rate was 22.3 percent (n = 25). Complications by flap type varied without reaching statistical significance. CONCLUSIONS: Microvascular reconstruction in complex scalp defects is associated with successful outcomes, and chronologic age does not increase mortality or catastrophic flap complications. The most common flaps used to repair scalp defects are anterolateral thigh and latissimus dorsi, but a superior flap type could not be identified.

BACKGROUND: Despite inclusion of periorbital structures in facial transplants, critical assessment of posttransplantation short- and long-term periorbital function has not been reported. The purpose of this article is to report recovery of ocular and periorbital function, with critical appraisal of posttransplant blink in the setting of revision surgery. METHODS: Prospective ocular and periorbital functional assessments were completed at multiple time points in a patient undergoing facial transplantation and subsequent revision operations. Function was evaluated using clinical ocular examinations, visual acuity assessments, photography, and video at various intervals from preoperative baseline to 13.5 months after transplantation. During this period, revision operations involving periorbital structures were performed at 6 and 9 months after transplantation. RESULTS: Before transplantation, volitional blink was 100 percent in both eyes. Involuntary blink was 40 percent in the right eye and 90 percent in the left eye, with occasional full closure. Following face transplantation, voluntary blink was preserved, partial skin sensation was present, and involuntary blink improved to 70 percent in the right eye and 100 percent in the left eye. Following revision surgery, visual acuity and voluntary and involuntary blink were impaired. By 7.5 months after revision, improvement comparable to the pretransplantation assessment was observed. CONCLUSIONS: Adherence to principles of blink preservation is critical in periorbital transplantation. Involuntary blink is essential for preserving vision, and can be improved after transplantation. Revision surgery may temporarily impair advances made with initial allotransplantation. A comprehensive understanding of ocular biomechanics and function is invaluable to the reconstructive surgeon performing facial transplantation involving periorbital structures and posttransplant revision operations. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

BACKGROUND: Aesthetic and functional mandibular reconstruction can be achieved in 1-stage. It involves simultaneous dental implant placement in a free vascularized fibula transfer with a low-profile reconstruction plate. The aim of this study was to assess the postoperative aesthetic profile and oral functional result. MATERIAL AND METHODS: Ten patients with a mean age of 31.6 years and an average follow-up time of 83.7 months underwent 1-staged mandibular reconstructions after segmental mandibulectomies. Simultaneous dental implantation was placed at the fibular segment according to the maxillary dentition. The fibula-implant construct was stabilized superiorly with miniplates and an additional low-profile reconstruction plate recreated the inferior mandibular contour. Any remaining vascularized soft tissue was used for augmentation. Palatal mucosa grafts were placed around the dental implant healing abutment at the uncovering stage surface. Aesthetic profile and oral function were evaluated postoperatively for 5 years. RESULTS: All microsurgical transplantations were successful. None of the patients required subsequent revisions. All patients completed prosthodontic rehabilitation. All patients had palatal mucosal grafts placed around the dental implants. The mean probing pocket depths were shallower around the implants, 3.09 +/- 0.82 mm at mesial, 3.33 +/- 1.05 mm at distal, 3.02 +/- 1.13 mm at buccal, and 3.23 +/- 1.17 mm at lingual surfaces. Radiographs revealed no statistical differences in mean of the mesial [0.27 +/- 0.26 mm] and distal [0.33 +/- 0.25 mm] of peri-implant bone loss. The prosthetic load mean follow-up time was 71.7 months with a satisfactory implant-supported prosthesis. Two slender female patients palpated the reconstruction plate beneath the soft tissue envelope. CONCLUSIONS: This approach is selectively fashioned for patients with benign disease when the overlying soft tissue drape is adequate. The technique described results in improved appearance and function through definition of the lower third of the face and simultaneous dental implant replacement.

Vascularized bone flaps are the well-known standards of care for reconstruction of segmental mandibular defects ≥ 6 cm. We developed a large animal critical-sized mandibular defect model in which osseous free fibula flaps were used for reconstruction.In this study a total of eight 3-month-old Yorkshire pigs underwent 6 cm full-thickness resection of the left hemimandible. An osseous free fibula flap from the left leg was harvested and contoured to the mandibular defect. Bone placement and plate position was confirmed with fluoroscopy. Animals were followed with serial radiographs and clinical evaluations.Free fibulas were transferred successfully in all eight animals. The average operative time was 346 minutes, and the average flap ischemia time was 86 minutes. The average volume ratio of reconstructed hemimandibles to nonoperated control hemimandibles was 0.72 ± 0.33. The average maximum fracture load was 689 ± 262 N, and the average ratio of biomechanical fracture load for these samples compared with contralateral control hemimandibles was 0.88 ± 0.25.It is concluded that the porcine osseous free fibula flaps can be reliably harvested and viably transferred to critical-sized posterior mandibular defects with acceptable long-term results. The described microsurgical large animal model is acceptable for use in craniomaxillofacial experimentation.