Helen G. Hui-Chou

Incisional negative-pressure wound therapy versus conventional dressings following abdominal wall reconstruction: a comparative study.

BackgroundImprovements in surgical techniques have allowed us to achieve primary closure in a high percentage of large abdominal hernia repairs. However, postoperative wound complications remain common. The benefits of negative-pressure wound therapy (NPWT) in the management of open abdominal wounds are well described in the literature. Our study investigates the effects of incisional NPWT after primary closure of the abdominal wall. MethodsA retrospective chart review was performed for the period between September 2008 and May 2011 to analyze the outcomes of patients treated postoperatively with incisional NPWT versus conventional dry gauze dressings. Patient information collected included history of abdominal surgeries, smoking status, and body mass index. Postoperative complications were analyzed using &khgr;2 exact test and logistic regression analysis. ResultsFifty-six patients were included in this study; of them, 23 were treated with incisional NPWT, whereas 33 received conventional dressings. The rates of overall wound complications in groups I and II were 22% and 63.6%, respectively (P = 0.020). The rates of skin dehiscence were 9% and 39%, respectively (P = 0.014). Both outcomes achieved statistical significance. Rates of infection, skin and fat necrosis, seroma, and hernia recurrence were 4%, 9%, 0%, and 4% for group I and 6%, 18%, 12%, 9% for group II, respectively. ConclusionsThis study suggests that incisional NPWT following abdominal wall reconstruction significantly improves rates of wound complication and skin dehiscence when compared with conventional dressings. Prospective, randomized, controlled studies are needed to further characterize the potential benefits of this therapy on wound healing after abdominal wall reconstruction.

Frontobasal fractures: Anatomical classification and clinical significance

Background: Frontobasal injury is a classic craniomaxillofacial fracture affecting the anterior cranial base. No data exist regarding the degree of frontobasal injury and associated midfacial fractures. The authors propose a classification of frontobasal and midface fractures involving the cranial base based on cadaveric experiments and comprehensive clinical experience. Methods: An institutional review board–approved retrospective review was conducted on patients with frontobasal fractures from 1995 to 2005. Fractures were categorized by pattern, location, midfacial involvement (impure), and complications compiled. One hundred five cadaveric heads underwent blunt impact to the frontal bone and upper midface. Calvarial vault, cranial base, and midface fracture patterns were categorized. Results: Three frontobasal fracture patterns were identified. Isolated linear cranial base fractures constitute type I. Vertical-linear fractures of the skull vault (frontal bone) occur in combination with base fractures, representing type II (vault and base). Comminution of the frontolateral skull vault and orbital roof in association with a linear base fracture constitute type III. Two hundred ninety patients were identified with 49 complications (cerebrospinal fistula, 24; and infectious 25). Type III (n = 159) had the highest complication rate (impure, 29 percent; pure, 17 percent), followed by type II (impure, 19 percent; pure, 5 percent). There is essentially no extension of midface fractures to the cranial vault. Conclusions: Frontobasal fractures have three unique and reproducible patterns based on vector, location, and force. This new classification scheme, paired with known patterns of midfacial injuries, assists in fully understanding frontofaciobasal injury and its complications. Overwhelmingly, impure type II and any type III fractures are associated with a high rate of complications and must be carefully managed.

Total face, double jaw, and tongue transplant research procurement: an educational model.

Background: Transplantation of a facial vascularized composite allograft is a highly complex procedure that requires meticulous planning and affords little room for error. Although cadaveric dissections are an essential preparatory exercise, they cannot simulate the true clinical experience of facial vascularized composite allograft recovery. Methods: After obtaining institutional review board approval to perform a facial vascularized composite allograft research procurement, a 66-year-old, brain-dead donor was identified. The family graciously consented to donation of a total face, double jaw, and tongue allograft and multiple solid organs. Results: A craniofacial computed tomographic angiogram was obtained preoperatively to define the vascular anatomy and facilitate virtual computerized surgical planning. The allograft was procured in 10 hours, with an additional 2 hours required for an open tracheostomy and silicone facial impression. The donor was coagulopathic throughout the recovery, resulting in an estimated blood loss of 1500 ml. Fluorescence angiography confirmed adequate perfusion of the entire allograft based on lingual and facial arterial and external jugular and thyrolinguofacial venous pedicles. The solid organ transplant team initiated abdominal organ isolation while the facial allograft procurement was in progress. After completion of allograft recovery, the kidneys and liver were recovered without complication. Conclusions: Before conducting a clinical face transplant, adequate preparation is critical to maximize vascularized composite allotransplantation outcomes and preserve solid organ allograft function. As more centers begin to perform facial transplantation, research procurement of a facial vascularized composite allograft offers a unique educational opportunity for the surgical and anesthesia teams, the organ procurement organization, and the institution. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Prolonged Survival of Composite Facial Allografts in Non-Human Primates Associated With Posttransplant Lymphoproliferative Disorder

Background. Composite tissue allotransplantation may have different immunosuppressive requirements and manifest different complications compared with solid organ transplantation. We developed a non-human primate facial composite tissue allotransplantation model to investigate strategies to achieve prolonged graft survival and immunologic responses unique to these allografts. Methods. Composite facial subunits consisting of skin, muscle, and bone were heterotopically transplanted to mixed lymphocyte reaction-mismatched Cynomolgus macaques. Tacrolimus monotherapy was administered via continuous intravenous infusion for 28 days then tapered to daily intramuscular doses. Results. Five of the six animals treated with tacrolimus monotherapy demonstrated rejection-free graft survival up to 177 days (mean, 113 days). All animals with prolonged graft survival developed posttransplant lymphoproliferative disorders (PTLD). Three animals converted to rapamycin after 28 days of rejection of their allografts, but did not develop PTLD. Genotypic analysis of PTLD tumors demonstrated donor origin in three of the five analyzed by short-tandem repeats. Sustained alloantibodies were detected in rejecting grafts and absent in nonrejecting grafts. Conclusions. Tacrolimus monotherapy provided prolonged rejection-free survival of composite facial allografts in a non-human primate model but was associated with the development of a high frequency of donor-derived PTLD tumors. The transplantation of a large volume of vascularized bone marrow in composite tissue allografts may be a risk factor for PTLD development.

Abdominal ventral hernia repair with current biological prostheses: an experimental large animal model.

Biologic prostheses have emerged to address the limitations of synthetic materials for ventral hernia repairs; however, they lack experimental comparative data. Fifteen swine were randomly assigned to 1 of 3 bioprosthetic groups (DermaMatrix, AlloDerm, and Permacol) after creation of a full thickness ventral fascial defect. At 15 weeks, host incorporation, hernia recurrence, adhesion formation, neovascularization, inflammation, and biomechanical properties were assessed. No animals had hernia recurrence or eventration. DermaMatrix and Alloderm implants demonstrated more adhesions, greater inflammatory infiltration, and more longitudinal laxity, but near identical neovascularization and tensile strength to Permacol. We found that porcine acellular dermal products (Permacol) contain following essential properties of an ideal ventral hernia repair material: low inflammation, less elastin and stretch, lower adhesion rates and cost, and more contracture. The addition of lower cost xenogeneic acellular dermal products to the repertoire of available acellular dermal products demonstrates promise, but requires long-term clinical studies to verify advantages and efficacy.

Clinical Applications of the Pedicled Anterolateral Thigh Flap in Complex Abdominal―Pelvic Reconstruction

Background:The free anterolateral thigh (ALT) flap has become a reconstructive workhorse with great versatility throughout the body. However, the utility of the pedicled ALT flap is less described for complex defects. A skin paddle with reliable blood circulation and wide range of reach, low donor site morbidity along with the avoidance of many of the complications plaguing free flaps, are just some of the several benefits offered by the pedicled ALT flap. We investigated specific clinical examples within our ALT flap database where the pedicled ALT flap was used for coverage of complex wounds and highlight its advantages. Methods:We conducted a retrospective chart review on those patients in whom a pedicled ALT flap was used for complex wound reconstruction over a 7-year period between July 2002 and October 2009 at The R Adams Cowley Shock Trauma Center performed by a single surgeon. Results:Four patients underwent a pedicled ALT flap as part of their reconstruction. Flaps ranged in size from 75 to 648 cm2, and all but one were cutaneous in nature with the other one being fasciocutaneous. The flaps averaged 2 perforators (range, 1–3) and the donor sites were all closed primarily except for one. Conclusions:When faced with a complex defect in the abdominal-pelvic region, we propose that the pedicled ALT flap has several advantages to other types of tissue coverage and is an excellent option for the reconstructive surgeon.

Secondary refinements of free perforator flaps for lower extremity reconstruction.

Background: The aim of lower extremity reconstruction has focused on early wound coverage and functional recovery but rarely aesthetics. Free muscle flaps provide durable coverage; however, they require skin graft coverage and result in muscle atrophy limiting future revisions. Perforator-based flap reconstructions can be easily elevated to allow for both orthopedic and contouring procedures. The authors reviewed the role of secondary procedures in achieving improved functional and aesthetic results following perforator flap reconstruction of lower extremity defects. Methods: A retrospective review identified 70 patients treated at R Adams Cowley Shock Trauma Center with 73 free perforator flaps for coverage of lower extremity wounds from 2002 to 2009. Results: Seventy patients were identified who underwent reconstruction with a perforator flap: 65 with anterolateral thigh flaps and five with superficial circumflex iliac artery flaps. Nineteen of these patients underwent 32 refinement procedures of the reconstructed limb. Fifteen refinements were performed with suction-assisted lipectomy, 21 with complex tissue rearrangement, including sharp debulking, and one with tissue expanders. Twenty-seven of the 70 patients underwent 40 orthopedic-related secondary procedures in which the free flap was elevated. The most common reasons for the orthopedic interventions were tibial nonunion requiring bone grafting (n = 17) and osteomyelitis (n = 11). Conclusions: Limb salvage remains the primary goal of lower extremity reconstruction. Following convalescence and functional recovery, however, appearance becomes increasingly important with regard to quality of life. Initial flap selection with free perforator flaps, meticulous inset, and secondary refinements provide superior functional and aesthetic outcomes.

Infrared fluorescence imaging of lymphatic regeneration in nonhuman primate facial vascularized composite allografts.

Background:Clinical vascularized composite allografts (VCA), although performed with good success, have been characterized by rejection episodes and postoperative graft edema. We investigated lymphatic donor-recipient reconstitution and lymphatic regeneration in a nonhuman primate facial VCA model. Methods:Heterotopic partial face (n = 9) VCAs were performed in cynomolgus macaques. Grafts were monitored for rejection episodes and response to immunosuppressive therapies as previously described. Donor and recipient lymphatic channels were evaluated using a near-infrared handheld dual-channel light-emitting diode camera system capable of detecting fluorescence from indocyanine green injections. Graft lymphatic channels were serially evaluated from postoperative day 0 to 364. Results:Preoperative imaging demonstrated superficial lymphatic anatomy similar to human anatomy. Initial resolution of facial allograft swelling coincided with superficial donor-recipient lymphatic channel reconstitution. Reconstitution occurred despite early acute rejection episodes in 2 animals. However, lymphatic channels demonstrated persistent functional and anatomic pathology, and graft edema never fully resolved. No differences in lymphatic channels were noted between grafts that developed transplant vasculopathy (n = 3) and those that did not (n = 6). Dynamic changes in patterns of lymphatic drainage were noted in 4 animals following withdrawal of immunosuppression. Conclusions:Donor-recipient lymphatic channel regeneration following VCA did not result in resolution of edema. Technical causes of graft edema may be overcome with alternative surgical techniques, allowing for direct investigation of the immunologic relationship between VCA graft edema and rejection responses. Mechanisms and timing of dynamic donor-recipient lymphatic channel relationships can be evaluated using fluorescent imaging systems to better define the immunologic role of lymphatic channels in VCA engraftment and rejection responses, which may have direct clinical implications.

Clinical Implications of Peripheral Myelin Protein 22 for Nerve Compression and Neural Regeneration: A Review

Peripheral myelin protein 22 (PMP22) is a major component of the peripheral myelin sheath. The PMP22 gene is located on chromosome 17p11.2, and defects in PMP22 gene have been implicated in several common inherited peripheral neuropathies. Hereditary neuropathy with liability to pressure palsies (HNPP), Charcot-Marie Tooth disease type 1A (CMT1A), Dejerine-Sottas syndrome, and congenital hypomyelinating neuropathy are all associated with defects in PMP22 gene. The disease phenotypes mirror the range of expression of PMP22 due to the corresponding genetic defect. HNPP, characterized by a milder recurrent episodic focal demyelinating neuropathy, is attributed to a deletion leading to PMP22 underexpression. On the other end of the spectrum, CMT1A leads to a more uniform demyelination and axonal loss, resulting in severe progressive distal weakness and paresthesias; it is due to a duplication at 17p11.2 leading to PMP22 overexpression. Additional point mutations result in varying phenotypes due to dysfunction of the resultant PMP22 protein. All inherited neuropathies are diagnosed with a combination of physical findings on examination, electromyography, sural nerve biopsies, and genetic testing. Treatment and management of these disorders differ depending on the underlying genetic defect, nerves involved, and resulting functional impairments. A review of current literature elucidates clinical, microsurgical implications, and management of patients with PMP22-related neuropathy.

Utilization of Near-infrared Indocyanine Green Angiography for Immediate and Delayed Venous Outflow Assessment in Breast Reconstruction: A Case Report.

Supplemental Digital Content is available in the text.