Effects of subcutaneous expansion on the mechanical properties of porcine skin.

The purpose of this study was to determine the effects of conventional and intraoperative tissue expansion on the biomechanical properties of skin. Two 200-cc silicone tissue expanders were inserted subcutaneously in each of six young pigs. One expander was inflated conventionally (4 weeks) and the other intraoperatively (three times within 1 hr). A skin specimen was excised from each expansion site and each contralateral control site and tested under tension to failure. The sites were closed and allowed to heal for 4 weeks at which time another biopsy specimen was taken from each site. Histological observations and biochemical analyses were conducted. Also, tangent modulus and ultimate stress were determined from the mechanical response of each specimen. Results indicated an initial decrease in stiffness and ultimate strength for conventionally expanded skin. The mechanism for this decrease could not be explained via our current biochemical and histological techniques. Mechanical properties for conventionally expanded skin, after healing, were not significantly different than controls. The mechanical properties for intraoperatively expanded skin were not significantly altered with respect to controls, either at initial expansion or after 4 weeks of healing. The tissue "generated" as a result of intraoperative expansion in the porcine model is likely tissue recruited from the surrounding skin.

Latissimus-sparing thoracotomy in the pediatric patient: a valuable asset for thoracic reconstruction.

The traditional posterolateral thoracotomy involves division of the latissimus dorsi muscle (LD). While the division results in no functional disability, it does negate the potential for possible future thoracic reconstruction if required in individual cases (eg, bronchopleural fistula, empyema, etc). A latissimus-sparing thoracotomy (LST) mobilizes the muscle dorsad and does not compromise the operation. Thus, the ipsilateral LD can be used when chest wall reconstruction is required. This option has been used frequently for adults; however, its use in children has not been extensively documented. Microvascular anastomoses for a contralateral LD free-flap may be tenuous in the small vessels of the child; thus, reconstruction using the ipsilateral LD could be beneficial and safer. The feasibility of LST has not been established with regard to the chest of the child. The authors present three pediatric thoracic cases that illustrate the value of this procedure, and discuss different situations in which latissimus-sparing thoracotomy is advantageous.

Combined second and third toe transfer.

Historically, restoration of hand function following multiple digital amputation has been unsatisfactory. The evolution of digital reconstruction with toe transfer has enabled surgeons to reestablish prehension in these severely injured hands. A 4-year experience with 26 consecutive combined second and third toe transfers to replace missing adjacent fingers was reviewed in order to delineate the indications and technical considerations and to emphasize prevention of donor-site complications. Combined second and third toe transfer is reserved for adjacent finger amputations proximal to the digital web space with remaining fingers no longer than the small finger. Radial amputations are replaced with contralateral combined toe units, while ipsilateral toes are more ideal for ulnar amputations. Limited dorsal and plantar skin flaps extending only to the midpoint of the first and third digital web spaces allow for direct donor-site closure and uncomplicated healing. Maintenance of the plantar metatarsal arch by avoiding metatarsal shaft osteotomies or bone grafting-shortened metatarsals eliminates potential gait disturbances. When properly applied in selected patients, this single-stage microsurgical procedure can restore prehensile function, improve the appearance of the hand with multiple digital amputations, and preserve near-normal donor-foot function.

Groin flap design and versatility.

The groin flap is a reliable and well-established reconstructive option for pedicled or free-tissue transfer. Concern regarding its variable vascular origin and caliber has limited its use. To overcome this, a simplified guideline based on the transverse diameter of the patient's index and long fingers at the distal interphalangeal level has been developed. Thus "rule of two finger widths" positions the origin of the vascular pedicle from the femoral vessels two finger widths below the inguinal ligament, the upper flap border two finger widths above the inguinal ligament, the lower flap border two finger widths below the vascular origin, and both parallel to the flap axis, which lies along a line from the vascular origin to the anterosuperior iliac spine. This new groin flap design provides the necessary guidelines for vascular identification, accommodates pediatric and adult stature, and ensures primary donor-site closure if flap dimensions are within the prescribed boundaries. In addition, a new sartorius-cutaneous groin flap is presented. This combines the cutaneous groin flap with the proximal sartorius muscle (up to 15 cm), which is supplied by the deep vessels of the superficial circumflex iliac system. The sartorius-cutaneous groin flap further emphasizes the concept of single-pedicle compound or combined flaps and additionally enhances the extensive reconstructive versatility of previously described groin flaps. Over 200 pedicled and free groin flaps have been performed according to the "rule of two finger widths" over the past 5 years. There have been no complications related to flap design, such as difficulty with flap elevation, marginal necrosis, or donor-site closure.(ABSTRACT TRUNCATED AT 250 WORDS)

Microsurgical restoration of distal digital function.

Advances in microsurgery have produced multiple options for microsurgical restoration of distal digital function. However, because of the complexity of most mutilating hand injuries, these possibilities can be readily overlooked. A surgical awareness of these options for "like" tissue transplantation is now necessary for complete mutilating hand injury care. These "minor" aesthetic and functional microsurgical procedures can be major factors in overall patient acceptance and utilization of the reconstructed hands.

Microsurgical reconstruction of opposable digits in mutilating hand injuries.

Multilating hand injuries with multiple digital amputations require a cooperative patient, a highly skilled hand/microsurgical team, and a continuum of hand rehabilitation therapy for optimal functional salvage. A systematic approach for assessing a patient's functional deficit and reconstructive requirements contributes to a coordinated reconstruction and rehabilitation plan designed to optimize functional gains. Today's sophisticated microsurgical reconstruction coupled with comprehensive hand therapy generally represents the best option for patients with mutilating hand injuries. Throughout reconstruction and rehabilitation the ultimate goal of multilating hand injury care, that of restoring a functional extremity that is useful in a patient's daily life must be remembered.