Faculty Bibliography

In vivo reconstitution of the dTDP-D-desosamine pathway of the megalomicin gene cluster from Micromonospora megalomicea was achieved by expression of the genes in Escherichia coli. LC/MS/MS analysis of the dTDP-sugar intermediates produced by operons containing different sets of genes showed that production of dTDP-D-desosamine from dtdp-4-keto-6-deoxy-D-glucose requires only four biosynthetic steps, catalysed by MegCIV, MegCV, MegDII and MegDIII, and that MegCII is not involved. Instead, bioconversion studies demonstrated that MegCII is needed together with MegCIII to catalyse transfer of D-desosamine to 3-alpha-mycarosylerythronolide B.

BACKGROUND: Large nipples, disproportionate to the small areola and breast size, are an ethnic characteristic frequently encountered among Asian female patients. Patients seek correction to improve cosmesis and alleviate psychological and physical discomfort. The authors present a new technique of nipple reduction and describe its potential advantages over other techniques. METHODS: Between March of 2003 and April of 2005, 34 nipple reductions were performed in 19 female patients (mean age, 40.5 +/- 5.6 years) using the modified top hat flap. The neonipple is designed to reduce the nipple diameter at the superior pole of the nipple while preserving the subdermal plexus. A crescent-shaped section of nipple skin below the proposed neonipple is excised, maintaining the integrity of the neonipple and the central nipple core. Two lateral wing flaps are elevated and trimmed to reduce both nipple height and diameter at the lateral walls of the nipple. The flaps of the neonipple are then sutured to the areola. RESULTS: Postoperative recovery was rapid and uneventful and no complications were encountered. The mean diameter of the hypertrophic nipple was 16.3 +/- 2.6 mm (range, 16 to 30 mm). The mean diameter of the neonipple was 7.9 +/- 1.7 mm (range, 5 to 11 mm), with an average reduction of 8.4 +/- 1.6 mm (range, 5 to 20 mm). At 17.2 +/- 2.9 months of follow-up, the neonipple had a natural appearance, with less projection and an inconspicuous scar. There was no statistically significant difference on monofilament sensation testing (p = 0.5829) between reduction nipple and areola in 11 nipples of seven patients. CONCLUSIONS: The modified top hat flap requires minimal preoperative planning, is easy to perform, and yields reproducible results. This technique decreases both the diameter and height of any size nipple and can be modified to meet patient preferences. Because the continuity of the neonipple with the subdermal arterial plexus is maintained and the majority of the parenchymal elements are preserved, nipple sensation and circulation remain largely unaffected.

BACKGROUND: To evaluate the impact of damage control laparotomy on long term morbidity and survival. METHODS: Prospective data were collected on 56 consecutive trauma patients over a 20-month period (May 2000-January 2002). Patients were stratified by mechanism of injury, age, Injury Severity Score, and type of injury, temperature at admission, initial blood transfusion volume and pH. Initial outcome data included major complications, intensive care unit and hospital length of stay, and mortality. Readmission data including number of admissions, surgical procedures, and hospital length of stay were then analyzed over the subsequent follow-up years (2001-2003). RESULTS: The mean age of the study group was 31 +/- 11 years with a mean Injury Severity Score of 33 +/- 13. The majority of the patients were male (73%) with a relatively equal number of blunt (n = 30) and penetrating injuries (n = 26). Liver injuries (34 [61%]) were the most common solid organ injury followed by 22 bowel (39%), 19 spleen (34%), 11 major vessel (20%), and 7 pancreas (13%) injuries. The mean number of initial abdominal surgical procedures was 4.4 +/- 2.2 per patient. The overall mortality during the first admission was 27%. Time spent in the intensive care unit and hospital length of stay was 17 +/- 13 and 30 +/- 19 days, respectively. There were a total of 74 readmissions and 58 subsequent surgical procedures in the 41 patients who were readmitted. Thirty-one (76%) patients were re-admitted at least one time. Infection (n = 19) was the most common reason for readmission followed by ventral hernia repair (n = 17) and fistula management (n = 14). There was 0% mortality for patients who survived the preliminary hospitalization but required readmission. CONCLUSION: Although damage control laparotomy is associated with a significant complication and readmission rate, its long term survival and benefit is indisputable.

Traumatic maxillary bone loss, if not treated acutely, is accompanied by contracture of the overlying soft tissue envelope and loss of facial projection in three dimensions. Reconstruction aimed at replacing the bony architecture, expanding the soft tissue envelope and establishing a platform for dental rehabilitation can be accomplished in a staged approach. We present two patients who underwent replacement of missing maxillary segments with a free fibula flap, followed by distraction of the free fibula in three dimensions and eventual dental rehabilitation with osseo-integrated implants.

Various local and distant flaps have been used to repair pelvic defects, including sartorius, rectus abdominis, rectus femoris, tensor fascia lata, vastus lateralis, gracilis, and omentum, each with benefits and disadvantages. The pedicled internal oblique rotational muscle flap has been described to cover pelvic wounds but may be underutilized. We present our experience with 5 pedicled internal oblique flaps in 4 patients (3 male, 1 female). The mean patient age was 32 years (23-47 years), and the mean follow-up was 8 months. All patients required coverage of the lateral pelvis after failure of conservative measures. There were no major complications. One patient experienced decreased sensation in the lateral femoral cutaneous nerve distribution, which resolved fully within 3 months. The internal oblique muscle provides local soft-tissue coverage with a predictable blood supply, and its proximity to the pelvis offers an alternative for reconstruction of lateral pelvic defects, with minimal associated morbidity.

A 50-year-old right-handed male presented with a previously incompletely excised low-grade fibrous histiocytoma on his distal radial palmar forearm. Reoperative wide resection resulted in a segmental defect of the radial artery and a large soft-tissue defect with exposed tendons denuded of paratenon. An arterialized venous fasciocutaneous flow-through flap, measuring 8 x 3 cm, was harvested from the dorsal ipsilateral hand and used to reconstruct both the soft-tissue and the segmental radial-artery defects. A full-thickness skin graft was harvested from the ipsilateral groin to cover the dorsal hand wound. Moderate venous congestion was noted in the flap on postoperative day 1 and treated with four days of leeches. Approximately 10 percent of the flap was lost due to the venous congestion. The flap healed well without further complications. At 33 months the flap remained well-perfused, with excellent flow through the reconstructed radial artery evidenced by both clinical examination and by color vascular Doppler exam. The patient had full range of motion in his right hand despite initial postoperative stiffness and reported no cold intolerance in the right hand. There has been no local recurrence of the sarcoma. The authors believe that this is the largest arterialized venous flow-through flap currently reported to have survived, as well as the first reported case of its use for the simultaneous reconstruction of a radial artery defect and an associated soft-tissue loss.

The use of prosthetic mesh for the tension-free repair of incisional hernias has been shown to be more effective than primary suture repair. Unfortunately, prosthetic materials can be a suboptimal choice in a variety of clinical scenarios. In general, prosthetic materials should not be implanted into sites with known contamination or infection because they lack an endogenous vascular network and are thus incapable of clearing bacteria. This is of particular relevance to the repair of recurrent hernias, which are often refractory to repair because of indolent bacterial colonization that weakens the site and retards appropriate healing. Although fascia lata grafts and muscle flaps can be employed for tension-free hernia repairs, they carry the potential for significant donor site morbidity. Recently, a growing number of clinicians have used human acellular dermal matrix as a graft material for the tension-free repair of ventral hernias. This material has been shown to become revascularized in both animal and human subjects. Once repopulated with a vascular network, this graft material is theoretically capable of clearing bacteria, a property not found in prosthetic graft materials. Unlike autologous materials such as fascial grafts and muscle flaps, acellular dermal matrix can be used without subjecting the patient to additional morbidity in the form of donor site complications. This article presents a thorough review of the current literature, describing the properties of human acellular dermal matrix and discussing both animal and human studies of its clinical performance. In addition to the review of previously published clinical experiences, we discuss our own preliminary results with the use of acellular dermal matrix for ventral hernia repair in 46 patients.