Kenneth Hui

Gene expression of transforming growth factor beta-1 in rabbit zone II flexor tendon wound healing : Evidence for dual mechanisms of repair

&NA; The postoperative outcome of hand flexor tendon repair can be complicated by adhesions between the repair site and surrounding tissue. To date, the biology of hand flexor tendon wound healing remains controversial— both intrinsic (resident tenocyte) and extrinsic (tendon sheath fibroblast and inflammatory cell) processes may contribute to repair. Transforming growth factor beta‐1 is a cytokine that plays multiple roles in wound healing but is also implicated in the pathogenesis of excessive scar formation. This study examines the activation of transforming growth factor beta‐1 mRNA in a rabbit zone II flexor tendon wound‐healing model. Forty New Zealand White rabbit forepaws underwent complete transection and repair of the middle digit flexor digitorum profundus tendon in zone II. Tendons were harvested at increasing time intervals (1, 3, 7, 14, 28, and 56 days) and analyzed by in situ hybridization and immunohistochemistry to determine the expression patterns of transforming growth factor beta‐1. A small number of tenocytes exhibited expression of transforming growth factor beta‐1 mRNA at baseline in nonwounded control tendon specimens. The surrounding tendon sheath in these control specimens also revealed low numbers of fibroblasts and inflammatory cells expressing transforming growth factor beta‐1 mRNA. In contrast, flexor tendons subjected to transection and repair exhibited increased signal for transforming growth factor beta‐1 mRNA in both resident tenocytes and infiltrating fibroblasts and inflammatory cells from the tendon sheath. These data demonstrate that (1) normal unwounded tenocytes and tendon sheath cells are capable of transforming growth factor beta‐1 production, (2) this cytokine is activated in the tendon wound environment, as evidenced by mRNA upregulation, and (3) the upregulation of this cytokine in both “intrinsic” tenocytes and “extrinsic” tendon sheath fibroblasts and inflammatory cells supports dual mechanisms for tendon repair. Because transforming growth factor beta‐1 is thought to contribute to the pathogenesis of excessive scar formation, the findings presented here suggest that perioperative biochemical modulation of transforming growth factor beta‐1 levels may help limit flexor tendon adhesion formation. (Plast. Reconstr. Surg. 100: 937, 1997.)

Serratus anterior-rib composite flap: anatomic studies and clinical application to hand reconstruction.

Because of its relative ease of dissection, increased length of the vascular pedicle, and excellent diameter for anastomosis, the serratus anterior-rib composite flap has been used to reconstruct bony and soft-tissue defects in the face and lower extremities. However, no data are available on optimal rib level or harvest location. The authors report the results of the vascular anatomy of this flap in 6 fresh cadavers and 2 clinical patients using this flap to reconstruct a defect in the hand. Arteriograms were performed through the thoracodorsal artery, and microscopic dissections were done at the rib periosteum. The sixth through the ninth ribs showed consistent filling of their respective intercostal vessels. The rib segments near the anterior axillary line had the most abundant communicating vessels between the serratus and the periosteum. In two patients, the serratus-rib composite free flap provided excellent bone and muscle length for reconstructing the first metacarpal defect.

Use of 20 cm or longer interposition vein grafts in free flap reconstruction of the trunk

&NA; Between January of 1993 and September of 1995, six microsurgical free tissue transplants were performed using saphenous vein grafts ranging from 20 to 39 cm in length. All six free flaps survived. Two wounds were caused by radiation injury and two by tumor resection. The remaining two free flaps were performed for contour deformity and spinal cord coverage. All of the recipient sites were located on the trunk. In each case, an arteriovenous loop was created before the microvascular anastomosis to the free flap. There was one arterial thrombosis requiring thrombectomy and revision of the anastomosis. Three patients developed minor wound complications that responded to local wound care. Each of the flaps successfully provided wound coverage, and in two cases the flaps tolerated further radiation results. Long interposition vein grafts can be used for difficult microsurgical reconstructive procedures with reliable results when no local recipient vessels are available. Versatility is therefore afforded in placement of the flap and the choice of recipient vessels, making this option a useful one in the treatment of complex wounds of the trunk. (Plast. Reconstr. Surg. 101: 1262, 1998.)

Free flap closure in complex congenital and acquired defects of the palate

&NA; Extensive palatal defects cause substantial morbidity, including nasal regurgitation, poor oral hygiene, loose‐fitting obturators, and difficulty with speech. Microvascular techniques allow the surgeon to repair these complex defects with a one‐stage reconstruction, in contrast to possible multistage local or regional flap reconstruction. In this retrospective review, the authors present their 5‐year experience with free flap coverage of extensive palatal defects. From 1993 to 1998, 6 patients underwent free flap coverage of large palatal defects. The etiology of the large palatal defects included trauma (N = 1), neoplasm (N = 4), and a recurrent congenital cleft palatal fistula (N = 1). Three patients underwent osteocutaneous radial forearm flaps and 1 patient underwent a fasciocutaneous radial forearm flap. The remaining 2 patients underwent rectus abdominis muscle flaps. The ipsilateral facial artery and vein were used as the recipient vessels in all patients. There were no intraoperative complications (surgical or anesthetic). Postoperatively, 2 patients had surgical evacuation of small flap hematomas. One patient underwent revision of the fasciocutaneous flap. All flaps survived. In our experience, the benefits of free flap reconstruction of complex palatal fistulas seem to outweigh the risks of the operation, with reliable longterm results. Turk AE, Chang J, Soroudi AE, Hui K, Lineaweaver WC. Free flap closure in complex congenital and acquired defects of the palate. Ann Plast Surg 2000;45:274‐279

Modification of the vertical rectus abdominis musculocutaneous (VRAM) flap for functional reconstruction of complex vulvoperineal defects.

Radical vulvoperineal ablations present challenging reconstructive dilemmas, especially when local metastatic spread requires distal vaginal and anal resection. Despite advances in vaginal salvage and sphincteroplasty, surface recontouring remains elusive because of the necessity to resurface a large, complex area that includes the mons, vulva, and fourchette. We describe a modification of the inferior-based vertical rectus abdominis musculocutaneous (VRAM) flap where the superior portion is split longitudinally to produce “tongue” flaps, which can resurface complex vulvoperineal wounds. By splitting the flap, one can resurface the vulva, provide an edge to reattach the vaginal cuff, and recreate the fourchette and line the anoderm after anoplasty. This musculocutaneous flap provides adequate contour and protection against radiation injury. Splitting of the flap is based on the vascular territory of the superior epigastric branches and their perforators and can be carried down to the level of their anastomosis, with the inferior system at the level of the umbilicus. The split VRAM flap has been used successfully in 3 patients with complex perineal wounds with excellent results and maintenance of vaginal patency.

Economics of microsurgical cases and routine cases in a medical center

This report describes the economic impact of microsurgical cases and routine plastic surgery cases in our medical center. The study is based on a financial analysis of the practices of two surgeons. Financial data of patient encounters (admission to the hospital or a surgical unit) identified with each surgeon were categorized into microsurgical and related cases and routine cases (including cosmetic procedures and general hand cases). Revenues, costs, and profits were tabulated. Data were analyzed for 2 fiscal years (1994‐95 and 1995‐96). Analysis of the first fiscal year showed that microsurgery encounters (n = 188) generated

One-stage reanimation of the paralyzed face using the rectus abdominis neurovascular free flap

4.4 million in revenue with a profit margin after direct costs of

Optimization of an injectable tendon hydrogel: the effects of platelet-rich plasma and adipose-derived stem cells on tendon healing in vivo.

2.5 million (57 percent) and a net profit, after indirect costs, of

The role of the plastic surgeon in the management of surgical infection.

1 million (23 percent). Routine encounters (n = 262) generated

Tendon regeneration with a novel tendon hydrogel: in vitro effects of platelet-rich plasma on rat adipose-derived stem cells.

1.7 million with a net loss of —