Faculty Bibliography

BACKGROUND:The most common clinical presentation of thoracic outlet syndrome stems from compression of the lower trunk of the brachial plexus or ulnar nerve. A plethora of anatomical variations have been implicated in the cause of thoracic outlet syndrome. Roos' identification and classification of scalene muscle and fibrous bands have added an additional dimension to understanding its cause and subsequent treatment. Understanding the anatomy and relationship of this band with the lower trunk of the brachial plexus is of paramount importance. METHODS:As part of the authors' long-term study of the type 3 band in relation to the brachial plexus, 70 embalmed cadavers were dissected to yield 100 first thoracic ribs. Fibrous bands, when present, were studied in relation to the brachial plexus. RESULTS:A fibrous band consistent with Roos' type 3 was identified and found to occur in 35 percent of first ribs and 41 percent of cadavers. The mean size was 3.45 × 0.27 cm. Origins and insertions are described. Contrary to Roos' own description, however, the authors observed that Roos' type 3 band was anterior to the T1 nerve root, creating a tunnel through which the T1 nerve root must pass before joining the C8 nerve root. CONCLUSIONS:The authors believe that the type 3 band, when present, can create a tunnel that compresses the T1 nerve root against the first rib, potentially predisposing susceptible individuals to thoracic outlet syndrome. Clinical studies are needed to determine whether correlations between type 3 bands and thoracic outlet syndrome exist.

Tissue engineering has largely focused on single tissue-type reconstruction (such as bone); however, the basic unit of healing in any clinically relevant scenario is a compound tissue type (such as bone, periosteum, and skin). Nanofibers are submicron fibrils that mimic the extracellular matrix, promoting cellular adhesion, proliferation, and migration. Stem cell manipulation on nanofiber scaffolds holds significant promise for future tissue engineering. This work represents our initial efforts to create the building blocks for composite tissue reflecting the basic unit of healing. Polycaprolactone (PCL) nanofibers were electrospun using standard techniques. Human foreskin fibroblasts, murine keratinocytes, and periosteal cells (4-mm punch biopsy) harvested from children undergoing palate repair were grown in appropriate media on PCL nanofibers. Human fat-derived mesenchymal stem cells were osteoinduced on PCL nanofibers. Cell growth was assessed with fluorescent viability staining; cocultured cells were differentiated using antibodies to fibroblast- and keratinocyte-specific surface markers. Osteoinduction was assessed with Alizarin red S. PCL nanofiber scaffolds supported robust growth of fibroblasts, keratinocytes, and periosteal cells. Cocultured periosteal cells (with fibroblasts) and keratinocytes showed improved longevity of the keratinocytes, though growth of these cell types was randomly distributed throughout the scaffold. Robust osteoinduction was noted on PCL nanofibers. Composite tissue engineering using PCL nanofiber scaffolds is possible, though the major obstacles to the trilaminar construct are maintaining an appropriate interface between the tissue types and neovascularization of the composite structure.

We conducted this Institutional Review Board-approved retrospective study to compare Aquacel Ag Hydrofiber dressing (Aquacel Ag) to a standard dressing for the treatment of partial thickness burns in children. We used the St. Christopher's Hospital burn center registry to identify 20 pediatric patients who had sustained partial thickness burns over a 10-month period. Ten of these patients had been treated with Aquacel Ag Hydrofiber dressing and 10 were treated with conventional Xeroflo gauze with Bacitracin Zinc ointment, the institutional standard of care for nonoperative partial-thickness burn wounds. Inclusion criteria included anyone with partial-thickness burns below the age of 18 years and in excellent baseline health. Exclusion criteria included inhalation injury, presence of full-thickness burns necessitating surgical debridement, cellulitic, or infected wounds, and percentage total body surface area involvement greater than 40%. Outcomes measured for the Aquacel Ag versus the Xeroflo gauze with Bacitracin Zinc ointment group included hospital length of stay (2.4 vs. 9.6 days), total number of in-house dressing changes (2.7 vs. 17.1), pain on a 10-point scale associated with dressing changes (6.4 vs. 8.2), total number of intravenous narcotic administrations (2.3 vs. 14.4), nursing time adjusted for percentage total body surface area (1.9 vs. 3.5 min), time to wound reepithelialization (10.3 vs. 16.3 days), and patient primary caregiver satisfaction score using a 4-point scale--with four delineating maximum satisfaction (3.8 vs. 1.8). Aquacel Ag proved to be a safe and effective means of treating partial thickness burns with a significant reduction in nursing time and patient pain involved with dressing changes.

Amputations and degloving injuries of the hand are highly disabling, especially when they affect the thumb. Dorsal metacarpal artery (DMCA)-based flaps have been well-documented in the literature for use in extensive degloving injuries of both dorsal and palmar aspects of the thumb surface. Modifications on these flaps, such as the bilobed island flap, offer additional advantages when larger surface areas or more distal defects of the thumb are present. We present a review of the literature on the DMCA flap and describe its use to salvage a partial survival of a thumb amputation through the metacarpophalangeal joint.

OBJECTIVE:To report the first single port access (SPA) adrenalectomy to minimize patient discomfort through a less invasive procedure. METHODS/RESULTS/RESULTS:We performed the first SPA in a 63-year-old, otherwise healthy Caucasian female who had a 4.5-cm left adrenal mass that was incidentally discovered on computed tomography scan of the abdomen and pelvis. Through a 2-cm single longitudinal supraumbilical incision extended down to the abdominal fascia, three 5-mm ports were placed through separate facial entry points, to make a triangular port arrangement. The adrenal vein was identified and ligated using hemoclips. The remainder of the dissection was done using hemocoagulation. The adrenal gland was extracted via an EndoCatch bag device by removing one 5-mm port and upsizing to a 12-mm port. CONCLUSION/CONCLUSIONS:We report on the first SPA adrenalectomy. Although this technology is still in its infancy, the use of a single port for surgery provides a means to provide a potentially better patient outcome with a less invasive procedure.

BACKGROUND:Fatty livers have chronic oxidative stress, which could activate several transcription factors. We hypothesized that fatty livers of obese rats have increased activation of signal transducers and activators of transcription-1 and transcription-3 (Stat-1 and Stat-3) and that tocopherol treatment will decrease Stat activation. METHODS:Obese (Ob) and lean (Ln) Zucker rats with or without tocopherol treatment were used. Western blots of liver nuclear and cytoplasmic extracts to assess phosphorylated and total Stat-3 and tyrosine kinases Jak-2 and Tyk-2, immunohistochemistry to assess distribution of phosphoStat-3, and gel shift assays to assess Stat and nuclear factor kappa B binding were performed. Interleukin-6 serum levels and hepatic transcripts were determined by immunoassay and reverse polymerase chain reaction with Southern blotting, respectively. RESULTS:Livers of Ob animals had increased nuclear phosphoStat-3, decreased cytoplasmic Stat-3, and increased Stat-3 binding. Serum interleukin-6 was not measurable in either Ob or Ln animals and hepatic transcript levels were not significantly different. Tocopherol administration decreased nuclear phosphoStat-3, increased cytoplasmic Stat-3, and decreased Stat-3 binding activity. CONCLUSIONS:Chronic oxidative stress in fatty livers is associated with increased Stat-3 activation and decreased cytosolic Stat-3. Tocopherol treatment decreases Stat-3 activation and increases cytosolic Stat-3. Tocopherol-induced changes in Stat-3 may play a role in its beneficial effects in hepatic ischemia in fatty livers.