Lucio Pereira

Pretreatment computed tomographic gross tumor volume as predictor of persistence of tracheostomy and percutaneous endoscopic gastrostomy tube in patients undergoing larynx preservation

Although larynx preservation affords patients improvements in laryngectomy‐free survival, little has been reported regarding the functional outcomes after larynx preservation. The purpose of this study was to report the predictive value of pretreatment CT‐gross tumor volume (GTV) for persistence of tracheostomy and percutaneous endoscopic gastrostomy (PEG) tube in larynx preservation patients.

Stability of Midface Fracture Repair Using Absorbable Plate and Screw System Pilot Holes Drilled and Pin Placement at Angles Other Than 90

IMPORTANCE Conventional plating systems use titanium plates for fixation of fractures, with benefits of strength and biocompatibility. However, titanium plates require that screws be placed at a 90° angle to the pilot holes. In the midface, this becomes extremely difficult. Today, a variety of craniomaxillofacial osteosynthesis systems are available, including resorbable plating systems. Specifically, the KLS Martin Sonic Weld system ultrasonically fuses the plate and the head of the pin when placed and will fill the pilot hole grooves completely even at less than 90° angles, which provides a tremendous advantage in midface fracture repair. OBJECTIVE To determine if the KLS Martin Sonic Weld system provides plate-screw construct stability in human heads even when placed at acute angles at the midface buttresses. DESIGN, SETTING, AND SPECIMENS: Twenty cadaveric head specimens with the mandible removed were prepared by creating osteotomies in the midface buttresses bilaterally. Specimens were defleshed and placed in a 2-part testing rig to hold and position the head for testing in a standard material testing system. Testing was performed at the Wayne State University Bioengineering test laboratories, Detroit, Michigan, using an Instron device and high-speed camera. Specimens were plated on one side of the midface using the KLS Martin Sonic Weld system with pilot holes and pins placed at 90° angles. On the contralateral side, the buttresses were plated with the KLS Martin Sonic Weld system at 60°, 45°, and 30° angles. Data were collected using the TDAS data acquisition system and were compared with matched pairs within each specimen. MAIN OUTCOMES AND MEASURES Ultrasonically vibrated pins placed into absorbable mini-plates at less than 90° angles with the KLS Martin Sonic Weld system were compared with the same amount of stress as the system placed at a 90° angle before demonstrating plate-screw construct failure. RESULTS Fifty-seven paired tests were collected, with 114 total tests. Twenty failures were due to bone breakage, and 94 fixations failed as a result of the plate-screw construct breaking. Fractures fixated with the ultrasonic absorbable plating system placed with screws at all tested angles failed at similar loads to our control plates with pins placed at 90° angles. These results lend the surgeon to successfully reduce fractures in the midface fragments in difficult-to-reach areas and possibly cut down on operative time while improving the chance of achieving a long-lasting adequate reduction. CONCLUSIONS AND RELEVANCE Although there is a measured difference in the laboratory, no clinical difference is observed because the maximum force is not usually encountered. Overall, the clinical scenario indicates absorbable plates to be a viable option in less accessible areas. LEVEL OF EVIDENCE NA.

Microanatomy of Peripheral Facial Nerve Revisited

Objectives: Describe extraparotid course of the facial nerve via microsurgical dissection. Analyze branch distribution and endpoint muscle innervation. Methods: Ten cadaveric hemifaces dissected under surgical microscopes. Facial nerve was identified from stylomastoid foramen to muscle. MAS measured number, length, and width at border of parotid, at level of the pes anserinus, and muscle border (frontalis, orbicularis oculi, zygomaticus major, and depressor anguli muscles). Analysis of variance and Student T test were performed. Results: At parotid border, zygomatic and buccal branches branched more often than temporal or marginal mandibular branches (2.7 +1.0, 2.9 + 0.7 vs 1.8 +1.2, 2.1 +0.9 mm respectively; p=0.06), branch diameter (1.1+0.3, 1.0+0.5 vs 0.9+0.3, 0.9+0.3 mm respectively p=0.238). At muscle border, similar results were found for zygomatic and buccal branches compared to temporal or marginal mandibular branches (2.3+1.3, 3.1+1.0 vs 1.3+0.5,1.3+0.5mm; P = 0.001), diameter (0.9+0.4, 1.0+0.4 vs 0.8+0.3, 0.7+0.3mm; p=0.737). Zygomaticotemporal pes showed more branching and greater diameter compared to cervicofacial, (7.6+2.2 vs 2.6+0.5mm; P =.0001) and (2.5+0.9 vs 1.9+0.4mm; p=0.10) respectively. Branch length from pes to muscle was consistent, the longest being temporal, zygomatic, marginal mandibular, and buccal (9.6 + 1.2, 8.3 +1.4, 8.0 +1.3, 7.4 +0.9 cm respectively; p=0.007). Anastomosis between temporal/zygomatic and zygomatic/buccal branches were found more consistently across all specimens than buccal/marginal mandibular anastomosis. Conclusions: Consistently fewer branches of the marginal mandibular branch at parotid border and at muscle border, and fewer anastomoses, may be the reasons for increased morbidity from surgical injury. Histologic analysis will further elucidate the number of innervations to the muscles of facial function.

Stability of Midface Fracture Repair Using Absorbable Plates

Objective: Determine if the KLS Martin Sonic Weld system provides plate-screw construct stability in human skulls even when placed at acute angles at the midface buttresses. The strength of the construct will be compared with absorbable miniplates with screws placed at 90-degree angles. Method: Ten skulls will be prepared by creating midface osteotomies bilaterally. All screws will be placed at 90 degrees on the control side. The contralateral side will be plated with the absorbable system at more acute angles. The data will be compared as matched pairs within each specimen and statistically analyzed. Results: Fractures fixated with the ultrasonic absorbable plating system placed with screws at all tested angles will fail at similar to our control plates placed at 90 degrees. This will allow the surgeon to successfully reduce fractures in the midface fragments in difficult to reach areas and possibly cut down on operative time and improve the chance of achieving a long lasting adequate reduction. Conclusion: There is no difference in the strength of the plate-screw construct using the ultrasonic plate-pin system between pins placed at the conventional 90° or at more acute angles. This is likely a function of the design of the plating system.

Utility of Abdominal Computed Tomography in Head and Neck Cancer Patients

Objective: Assess the role of abdominal computed tomography (CT) imaging in the staging and surveillance of patients with head and neck squamous cell cancer (HNSCC) for distant metastatic disease (DMD) and second primary tumors (SPT). Method: Retrospective review of 172 HNSCC patients treated at an academic center who underwent abdominal CT imaging from 2003 to 2007. These scans were categorized as suspicious, positive, or negative for DMD or SPT. Charts of patients with suspicious or positive results were reviewed to determine resultant work-up and outcomes. Results: After consideration of exclusion criteria, 165 patients were included in this retrospective study. Normal abdominal CT scans were seen in 139 patients while the remaining 27 patients had abnormal abdominal CT findings. Of these 27, 16 patients (9.7%) were determined to have malignancy. Twelve patients had DMD, and 4 were diagnosed with SPT. Conclusion: Abdominal CT imaging identified DMD or SPT in 9.7% of patients resulting in significant alteration in their comprehensive oncologic care. This rate is not inconsequential and might justify the use of abdominal CT in managing HNSCC patients. Prospective trials might help determine the impact of abdominal CT findings on survival.