Joseph L. Edmonds

Osteocutaneous radial forearm free flaps. The necessity of internal fixation of the donor-site defect to prevent pathological fracture.

Background: Osteocutaneous radial forearm free flaps have fallen from favor due to pathological fractures of the radius. The purposes of this study were to propose a means to decrease the rate of pathological fracture by prophylactic fixation of the donor-site defect and to evaluate this technique biomechanically. Methods: Two groups of ten matched pairs of fresh-frozen cadaveric radii were harvested. In Group 1, an eight-centimeter length of radius comprising 50 percent of the cross-sectional area of the bone was removed to simulate an osteocutaneous radial forearm donor-site defect. This defect was created in one member of each pair, with the other bone in the pair left intact. In Group 2, both members of the ten matched pairs of radii had identical defects created as previously described. However, one radius in each pair had a twelve-hole, 3.5-millimeter dynamic compression plate placed across the segmental defect. In each group, five matched pairs were tested to failure in torsion and five matched pairs were tested to failure in four-point bending. Results: In Group 1, the intact radius was a mean of 5.7 times stronger in torsion and 4.2 times stronger in four-point bending than the radius with the segmental resection. In Group 2, the radius that was ostectomized and fixed with a plate was a mean of 4.0 times stronger in torsion and 2.7 times stronger in four-point bending than the ostectomized radius. Conclusions: Removal of an eight-centimeter segment from the radius dramatically decreased both torsion and bending strength. Application of a plate over the defect in the radius significantly restored the strength of the radius (p = 0.01). Clinical Relevance: The segmental defect created in the radius when an osteocutaneous radial forearm free flap is harvested weakens the donor bone an unacceptable amount, resulting in a high risk of pathological fracture. We believe that prophylactic internal fixation of the donor-site defect with a plate restores strength to such a level that pathological fracture may be prevented, thus increasing the utility of the osteocutaneous radial forearm free flap.

Vascular tumors have increased p70 S6-kinase activation and are inhibited by topical rapamycin

Vascular tumors are endothelial cell neoplasms whose cellular and molecular mechanisms, leading to tumor formation, are poorly understood, and current therapies have limited efficacy with significant side effects. We have investigated mechanistic (mammalian) target of rapamycin (mTOR) signaling in benign and malignant vascular tumors, and the effects of mTOR kinase inhibitor as a potential therapy for these lesions. Human vascular tumors (infantile hemangioma and angiosarcoma) were analyzed by immunohistochemical stains and western blot for the phosphorylation of p70 S6-kinase (S6K) and S6 ribosomal protein (S6), which are activated downstream of mTOR complex-1 (mTORC1). To assess the function of S6K, tumor cells with genetic knockdown of S6K were analyzed for cell proliferation and migration. The effects of topical rapamycin, an mTOR inhibitor, on mTORC1 and mTOR complex-2 (mTORC2) activities, as well as on tumor growth and migration, were determined. Vascular tumors showed increased activation of S6K and S6. Genetic knockdown of S6K resulted in reduced tumor cell proliferation and migration. Rapamycin fully inhibited mTORC1 and partially inhibited mTORC2 activities, including the phosphorylation of Akt (serine 473) and PKCα, in vascular tumor cells. Rapamycin significantly reduced vascular tumor growth in vitro and in vivo. As a potential localized therapy for cutaneous vascular tumors, topically applied rapamycin effectively reduced tumor growth with limited systemic drug absorption. These findings reveal the importance of mTOR signaling pathways in benign and malignant vascular tumors. The mTOR pathway is an important therapeutic target in vascular tumors, and topical mTOR inhibitors may provide an alternative and well-tolerated therapy for the treatment of cutaneous vascular lesions.

Torsional strength of the radius after osteofasciocutaneous free flap harvest with and without primary bone plating.

The osteocutaneous radial forearm free flap (OCRFFF) has not gained widespread popularity in mandibular reconstruction, primarily because of concerns about pathologic fracture of the weakened radius. This study examines the effectiveness of plate fixation of the radius bone after harvest of the OCRFFF as a mechanism to minimize donor-site morbidity and increase the usefulness of the OCRFFF. Matched pairs of fresh human cadaveric radius bones were used in this study. Two study groups were designed. The first group was used to define the amount of strength lost after a typical bone graft harvest. The second group was designed to demonstrate how much torsional strength was regained by the application of an orthopedic reconstruction plate. Statistically significant results were obtained for both groups. In group 1, the strength of the cut bones compared with that of the unaltered bones was significantly decreased by 82% (P = 0.016). In group 2, the cut bones reinforced with a plate were 75% stronger (P = 0.002) than the bones that were only cut. Although the radius bone is significantly weakened by the harvest of a graft, much of this strength can be regained with plate fixation of the radius. (Otolaryngol Head Neck Surg 2000; 123:400-8.)

Vagus nerve stimulation for drop attacks in a pediatric population

A retrospective analysis of 43 patients with drop attack seizures who were treated with vagus nerve stimulation (VNS) was undertaken to determine the efficacy of VNS and to determine pre-implantation characteristics associated with VNS success. It was found that on last follow-up, 46% of patients had at least a 75% reduction in drops per day. Forty-six percent of patients had less than a 50% reduction in drops per day and were considered nonresponders. Univariate analysis failed to uncover significant associations between pre-implantation characteristics and VNS success. It was found that atonic head nods were more amenable to VNS treatment as compared with atonic or tonic drop attacks. In addition, patients with focal or lateralized epileptiform abnormalities responded better to VNS compared with those with more diffuse or poorly localized findings on ictal and/or interictal recordings. Our data suggest that VNS offers significant palliative benefit to many children with medically intractable drop attack seizures.

Laryngotracheal separation surgery for intractable aspiration: Our experience with 12 patients

OBJECTIVE Laryngotracheal separation surgery (LTS) was performed as a treatment for recurrent or intractable aspiration pneumonia in 12 pediatric patients. The effectiveness of LTS surgery for preventing aspiration pneumonia, and the complications of this procedure were investigated. METHODS A retrospective chart review, conducted at a tertiary academic hospital in conjunction with a private practice, was used to identify children who underwent Laryngotracheal Separation Surgery (LTS) from September 2001 to July 2007. The main outcome measure was the number of hospital admissions for pneumonia in the pre LTS and post LTS period. A students t-test was used for statistical analysis. RESULTS LTS surgery decreased the frequency of pulmonary infections and respiratory events in all patients, resulting in far fewer hospitalizations. These patients experienced an average of 5 hospital admissions for pneumonia in the 2 years prior to LTS surgery, and an average of 1.1 hospital admissions for pneumonia after the LTS surgery. There were no major complications related to the surgery. Several minor complications following surgery were easily and effectively dealt with in the perioperative period. CONCLUSIONS LTS surgery is an effective and safe procedure in children with intractable aspiration. Parents do not perceive the care of the LTS stoma as burdensome. This procedure should be considered as an option in the surgical intervention for the management of chronic aspiration pneumonia in severely neurologically impaired children.

Surgical revision of vagus nerve stimulation electrodes in children

Use of vagus nerve stimulation (VNS) has increased in the past decade, resulting in frequent revision cases for device failure. The authors report their series of children who underwent reimplantation of the VNS device after removal of old electrodes and leads. Patients with medically refractory seizures who underwent revision of VNS electrodes were included (n = 23). Twenty patients had high lead impedance and underwent removal of the device and replacement of the VNS electrodes during the same procedure. In 3 patients, electrodes and the device had been removed previously at an outside institution because of infection. None of the patients experienced any major complications. Mean operative time was 2.3 ± 0.9 hours. The reimplanted device worked well in all patients, and seizure control was similar to or better than that reported with the previous device. Thus, implantation of the VNS electrodes is reversible, and it appears that the electrodes can be removed or replaced safely if the device is not functioning properly.

Pediatric recurrent laryngeal nerve reinnervation: A case series and analysis of post-operative outcomes

OBJECTIVE To provide detailed information about recurrent laryngeal nerve (RLN) reinnervation outcomes in children using objective measures. METHODS The records of three pediatric patients with unilateral vocal cord paralysis that underwent RLN reinnervation were retrospectively reviewed. Fundamental frequency (F0), jitter, shimmer, noise-to-harmonic ratio (NHR), and voice phonation (sustained /s/, /z/, /a/) were measured preoperatively and post-operatively at 13, 9, and 33 months (each time period corresponding to one of the three patients). RESULTS Mean preoperative and post-operative variables were as follows: shimmer, 9.65±1.02% vs. 4.46±0.71% (p=0.01); NHR, 0.296±0.063 vs. 0.127±0.011 (p=0.04); jitter, 3.57±0.89% vs. 1.46±0.54% (p=0.08); F0, 274.6±35.4Hz vs. 282.2±70.6Hz (p=0.44); maximum phonation time, 7.46±1.40s vs. 9.79±1.84s (p=0.22); /s:z/ ratio, 1.28±0.22 vs.1.07±0.09 (p=0.26). CONCLUSIONS There was statistically significant improvement in shimmer and NHR. Jitter improvement approached statistical significance. All other variables failed to show significant improvement among this small sample size. RLN reinnervation for pediatric patients is an option for the treatment of vocal cord paralysis. Further studies with larger cohorts are needed to show the full benefits.

Vascular anomalies and airway concerns.

Vascular anomalies, both tumors and malformations, can occur anywhere in the body, including the airway, often without any external manifestations. However, vascular anomalies involving the airway deserve special consideration as proper recognition and management can be lifesaving. In this article, the authors discuss vascular anomalies as they pertains to the airway, focusing on proper diagnosis, diagnostic modalities, and therapeutic options.

Case series: A novel technique for the treatment of external auditory canal stenosis

External auditory canal (EAC) stenosis can exist as an isolated problem, as a component of craniofacial disorders, or in association with genetic syndromes. We present five cases and demonstrate the efficacy of a minimally invasive way of opening the EAC, facilitating better hearing, easier office examination, and allowing for other necessary treatments such as ear tube placement or use of a hearing aid. Follow-up ranged from 1 to 19 months, with all patients demonstrating significant improvement. We believe this is a novel surgical approach which is easy to perform, cost effective, and may be applicable to a wide range of patients.

Syngnathia and obstructive apnea in a case of popliteal pterygium syndrome

AbstractWe describe an infant with popliteal pterygia, syngnathia, cleft lip and palate, and retrognathia diagnosed with popliteal pterygium syndrome (PPS). The neonatal course was complicated by severe obstructive apnea necessitating tracheostomy. Conclusion: This report illustrates the potential for airway compromise in PPS patients and the need for thorough neonatal airway assessment.