Nolan S. Karp

Lengthening the Human Mandible by Gradual Distraction

Lengthening of the mandible by gradual distraction was performed on four young patients (average age 78 months). The amount of mandibular bone lengthening ranged from 18 to 24 mm; one patient with Nagers syndrome underwent bilateral mandibular expansion. Following the period of expansion, the patients were maintained in external fixation for an average of 9 weeks to allow ossification. The patients were followed for a minimum of 11 months to a maximum of 20 months with clinical and dental examinations as well as photographic and radiographic documentation. The technique holds promise for early reconstruction of craniofacial skeletal defects without the need for bone grafts, blood transfusion, or intermaxillary fixation.

Membranous Bone Lengthening: A Serial Histological Study

Bone lengthening using the process of corticotomy and gradual distraction of callus is applicable to the membranous bone of the canine mandible. In this study the precursors to bone formation, in the area between the distracted bone edges, are analyzed in an attempt to determine the mechanism of bone formation. Ten mongrel dogs 5 months of age were studied. A unilateral, periosteal-preserving angular corticotomy was performed, and an external bone-lengthening device was fixed to the mandible. After 10 days of external fixation, the mandible was lengthened 1 ml per day for 20 days and then held in external fixation for 8 weeks. The dogs were killed for histological and microradiographic study at 10 and 20 days of distraction, and at 14, 28, and 56 days after the completion of distraction. It was observed that the gap between the distracted bone edges is first occupied by fibrous tissue. As distraction proceeds, the fibrous tissue becomes longitudinally oriented in the direction of distraction. Early bone formation advances along the fibrous tissue, starting from the cut bone ends. Eventually the area is converted to mature cortical bone. Bone is formed predominantly by intramembranous ossification. This mechanism is similar to that of bone formation during long bone lengthening.

The use of acellular dermal matrix in immediate two-stage tissue expander breast reconstruction.

Background: Acellular dermal matrix is commonly used in implant-based breast reconstruction to allow for quicker tissue expansion with better coverage and definition of the lower pole of the breast. This study was performed to analyze complications associated with its use in immediate two-stage, implant-based breast reconstruction and to subsequently develop guidelines for its use. Methods: A retrospective analysis of 628 consecutive immediate two-stage tissue expander breast reconstructions at a single institution over a 3-year period was conducted. The reconstructions were divided into two groups: reconstruction with acellular dermal matrix and reconstruction without it. Demographic information, patient characteristics, surface area of acellular dermal matrix, and complications were analyzed and compared. Results: A total of 407 patients underwent 628 immediate two-stage, implant-based breast reconstructions; 442 reconstructions (70.3 percent) used acellular dermal matrix and 186 (29.6 percent) did not. The groups had similar patient characteristics; however, major complications were significantly increased in the acellular dermal matrix group (15.3 versus 5.4 percent; p = 0.001). These complications included infection requiring intravenous antibiotics (8.6 versus 2.7 percent; p = 0.001), flap necrosis requiring excision (6.7 versus 2.7 percent; p = 0.015), and explantation of the tissue expander (7.7 versus 2.7 percent; p = 0.004). Conclusions: Use of acellular dermal matrix in immediate two-stage, implant-based breast cancer reconstruction is associated with a significant increase in major complications. Therefore, it should only be used in specific patients and in minimal amounts. Indications for its use include single-stage permanent implant reconstruction and inadequate local muscle coverage of the tissue expander. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Successful multimodal therapy for kaposiform hemangioendothelioma complicated by Kasabach-Merritt phenomenon: case report and review of the literature.

We present the management challenge provided by a patient with kaposiform hemangioendothelioma associated with Kasabach-Merritt phenomenon. A female child presented at 14 months of age with an ecchymotic swelling of her right upper arm and axilla. Subsequently, she developed profound thrombocytopenia and hypofibrinogenemia (Kasabach-Merritt phenomenon). Biopsy of the lesion revealed kaposiform hemangioendothelioma, which has been reported as the predominant pathologic diagnosis associated with Kasabach-Merritt phenomenon. To achieve involution of the lesion and preserve function of the arm, the following interventions were involved: embolization, systemic interferon, cyclophosphamide, epsilon aminocaproic acid, and compression therapy. The clinical management of this patient was formidable until we arrived at the proper combination of therapies. Multimodal intervention may be required to manage fastidious hemangioendotheliomas of childhood, achieve clinical improvement, and prevent further morbidity.

MICROVASCULAR FREE-FLAP SALVAGE OF THE DIABETIC FOOT : A 5-YEAR EXPERIENCE

This study reviews 21 microvascular free flaps to the diabetic foot in 19 patients over a 65-month period. All flaps were either to the plantar surface of the foot or to cover exposed Achilles tendon. Twenty of the flaps survived. The operations required a long, costly hospitalization with frequent recipient- and donor-site complications. All patients eventually ambulated on their flaps. Five patients came to proximal amputation from 6 to 37 months after surgery. Only one amputation was for flap breakdown.

The fate of lower extremities with failed free flaps.

&NA; This study reviews the outcome of patients with failed free Haps to lower extremities. The failure rate was 10 percent (41 of 413 flaps) over a 13‐year period. Trauma patients (83 percent of all patients) had a failure rate of 11 percent., while nontrauma patients had a failure rate of 6.7 percent. The most common cause of failure was venous thrombosis (34 percent). Eight of 36 patients (22 percent) went on to amputation after the failed free Hap; all were trauma patients. Patients with tibia‐fibula fractures had a 35 percent amputation rate (6 of 17 patients) after a failed free flap. Seventy‐eight percent of the patients (28 of 36) had salvage of their extremities by split‐thickness skin graft, local Haps, or a second free flap. Long‐term follow‐up was available in 24 of 36 patients (67 percent), 20 of whom were salvaged without amputation. Of the patients whose limbs were salvaged, none had undergone an amputation at a mean follow‐up of 6.2 years. All were ambulating, but 7 (35 percent) had intermittent wound breakdown. Despite an initial free‐flap loss, the majority of extremities can be salvaged with subsequent procedures. However, on long‐term follow‐up, a large percentage of patients continue to have wound problems. (Plast. Reconstr. Surg. 98: 834, 1996.)

MULTIDIMENSIONAL DISTRACTION OSTEOGENESIS : THE CANINE ZYGOMA

The principle of distraction osteogenesis, well-established in the enchondral bones of the axial skeleton, has recently been applied to the membranous bones (mandible, cranium) of the craniofacial skeleton in the experimental animal and in the human. In the craniofacial skeleton, however, the technique has been used only to lengthen bone in a direction along its major axis, i.e., unidimensional distraction. A canine model is presented to demonstrate the feasibility of distracting membranous bone away from its dominant axis, i.e., multidimensional distraction. Four mongrel dogs, 5 months of age, were the subjects of this study. Two osteotomies were made in the zygomatic arch, and the bone-lengthening device was fixed to the zygoma. After 7 days of external fixation, the osteotomized segment was lengthened 1 mm/day away from the long axis of the bone for 15 days. External fixation was then maintained for a minimum of 4 weeks, after which the dogs were sacrificed. Craniofacial CT with three-dimensional reconstruction documented multidimensional bone lengthening, and histologic analysis of the specimen confirmed the presence of new cortical bone in the expanded areas. Refinement in technique and miniaturization and internalization of the bone-lengthening device may allow for more precise changes in the amount and direction of lengthening, thus making distraction osteogenesis more widely applicable for use in the human craniofacial skeleton.

Wise-pattern breast reconstruction: modification using AlloDerm and a vascularized dermal-subcutaneous pedicle.

Immediate implant-based breast mound reconstruction offers many advantages over staged implant reconstruction techniques. For large volume breast reconstruction, a Wise-pattern skin resection may provide very good aesthetic results; however, the submuscular implant pocket is inadequate to cover the inferior pole of the breast. In this patient population, the risk of implant exposure from T-point breakdown is significant. We present our technique of Wise-pattern breast reconstruction using AlloDerm (LifeCell, Branchburg, NJ) and a vascularized dermal-subcutaneous pedicle (DSP) to augment the volume and quality of immediate breast implant coverage, particularly in the area of the T-point suture lines. We reviewed a series of 20 consecutive patients with large breasts who were treated with an immediate implant reconstruction of greater than 400 mL volume using the Wise-pattern with DSP. Preoperative and postoperative 3-dimensional surface scan studies were performed to evaluate breast symmetry. The average volume of breast reconstruction in this study group was 458 mL. T-point breakdown occurred in 5 patients (25%). These patients were treated with local wound care and healed with an excellent aesthetic result. None of these patients required implant removal, implant exchange, or operative debridement. Pre- and postoperative 3-dimensional surface scan analysis of these patients demonstrated comparable differences between the affected and unaffected sides in women undergoing immediate breast implant reconstruction when compared with a matched group of patients undergoing 2-stage breast reconstruction with tissue expanders. Wise-pattern skin-reducing mastectomy is an excellent strategy to provide an aesthetically pleasing, immediate implant breast reconstruction. This technique provides breast symmetry that is at least comparable to that of tissue expander-based, staged implant reconstructions. The reliability of the Wise-pattern technique is significantly improved with the addition of AlloDerm to the muscular pocket and a vascularized DSP to preserve the integrity of the reconstruction in the presence of T-point breakdown.

3D analysis of breast augmentation defines operative changes and their relationship to implant dimensions.

Breast augmentation is one of the most common plastic surgery procedures performed in the United States today. Evaluation of postoperative results lacks true objective measurements. The following study reports the application of 3-dimensional (3D) photography to document changes that occur in breast morphology after breast augmentation. Patients undergoing augmentation mammaplasty with a periareolar incision were offered pre- and postoperative 3D photographs. 3D models were constructed and the following parameters were assessed: maximum anterior-posterior projection from the chest wall, angle of breast projection, total breast volume, volumetric tissue distribution in the superior and inferior poles, and surface and vector distance measurements to key landmarks. A completed series of 3D images were obtained from 14 augmentation patients (28 breasts) at an average postoperative day of 143. Saline and silicone implants were used equally (n = 14 for each). Total volume of the breast changed in correlation with the implant size (1.9% difference, P = 0.83). There were no significant changes in the volumetric distribution within the upper and lower poles of the breasts noted between pre- and postoperative scans (P = 0.81). The internal angle of breast projection was found to increase (13.6 degrees, P < 0.01), as did the sternal notch to nipple distance (11 mm, P = 0.018). Anterior-posterior projection significantly increased by 23.3 mm. However, this increase in projection was 20.9% less than expected based on implant dimensions (72.7–58.7 mm, respectively, P < 0.01). This study documents objective changes in breast morphology after augmentation mammaplasty. 3D imaging scans were able to document true changes that occur with breast augmentation including breast volume, the increase in the internal angle of the breast projection, and the sternal notch to nipple distance. 3D photography further highlighted that breast augmentation results in less than expected anterior-posterior projection, possibly due to tissue attenuation occurring anterior to the implant.

The role of magnetic resonance imaging in the management of vascular malformations of the trunk and extremities.

&NA; Vascular malformations can usually be diagnosed on clinical grounds. They have a well‐defined appearance on magnetic resonance imaging, which can effectively determine their tissue and flow characteristics. However, the role of cross‐sectional imaging in the management of vascular malformations is not well defined. Most reviews suggest that magnetic resonance imaging should be reserved for cases in which the extent of the lesion cannot be estimated on physical examination. However, to date no group has compared the accuracy of physical examination alone to that of magnetic resonance imaging in determining this extent. A review was performed of all the patients evaluated for vascular malformations at the New York University Trunk and Extremity Vascular Anomalies Conference between July of 1994 and August of 1999. Patients who underwent magnetic resonance evaluation at other institutions and whose images were not available for review were excluded. All study patients either underwent magnetic resonance imaging examination at New York University Medical Center or had outside films reviewed at the center. The physical examination findings were compared with the magnetic resonance findings and the surgeon and radiologist made a joint decision about whether there was a correlation between the magnetic resonance and physical examination findings. Fifty‐eight patients met the study criteria, 44 (76 percent) of whom were found to have more extensive disease on magnetic resonance examination than appreciated on physical examination. Of the 51 patients with low‐flow vascular malformations (venous vascular malformations, lymphatic malformations, and capillary malformations), 39 (76 percent) had more extensive disease on magnetic resonance examination than on physical examination. Of the seven patients with high‐flow arteriovenous malformations, five had more extensive disease on magnetic resonance. In all of the 44 patients whose magnetic resonance imaging findings did not correlate with those of the physical examination, therapeutic decision making was affected. Contrary to the conventional wisdom of published reviews, physical examination findings significantly underestimated the extent of vascular malformations in the majority of cases. Magnetic resonance imaging should be performed in all patients with vascular malformations of the trunk and extremities before therapy is planned. In an age when physicians are asked to justify their decisions, especially where the use of expensive diagnostic modalities is concerned, the situations in which these tests are indispensable must be clearly defined or else patients will be denied access to them. (Plast. Reconstr. Surg. 112: 504, 2003.)