Lucie Lessard

Prevention of surgical site infection and appropriateness of antibiotic prescribing habits in plastic surgery

OBJECTIVES The use of antimicrobial prophylaxis against surgical site infection (SSI) is widespread in plastic surgery, while results from prospective randomised controlled trials in guiding antibiotic use are lacking. The purpose of this study was to identify the incidence and risk factors for SSI in plastic surgery, and to evaluate the appropriateness of prophylactic antibiotic prescribing habits in a tertiary university centre. METHODS A retrospective chart review was conducted over a 6-month period. Co-morbidities, types of procedure, prophylactic antimicrobial administration, SSI rates, and clinical outcomes were evaluated. RESULTS The incidence of SSI was 9.3% for 335 procedures. The cumulative incidence of SSI for breast surgery (n=80) was 16.3%, with a 78.8% prescription rate. For head and neck procedures (n=68), the incidence of SSI was 10.3%, with 80.9% of patients receiving antibiotic prophylaxis. For hand and upper limb procedures (n=170), 70.6% of patients received antimicrobial prophylaxis, with a 4.7% SSI incidence. According to category A prophylaxis guidelines published in the plastic surgery literature, over prescribing was identified in 27.5% of breast, 61.8% of head and neck, and 19.4% of hand and upper limb procedures. CONCLUSIONS This is the first study evaluating appropriateness of antimicrobial prophylaxis use by plastic surgeons. Despite widespread use of prophylactic antibiotics, significant SSI rates were still present and frequently responsible for re-hospitalisations and re-interventions. The appropriateness of administration and indications for perioperative prophylactic antibiotic use must be evaluated.

Utility scores for facial disfigurement requiring facial transplantation [outcomes article].

Background: Controversy exists as to whether the benefits of facial transplantation outweigh the risk of continuous immunosuppression. Utility scores [range, 0 (death) to 1 (perfect health)] are a standardized tool with which to objectify health states or diseases and can help answer such controversy. Methods: An Internet-based utility assessment study using visual analogue scale, time trade-off, and standard gamble was used to obtain utilities for facial disfigurement requiring facial transplantation from a sample of the general population and medical students at McGill University. Average utility scores were compared using t test, and linear regression was performed using age, race, and education as independent predictors of each of the utility scores. Results: A total of 307 people participated in the study. All measures (visual analogue scale, time trade off, and standard gamble) for facial disfigurement (0.46 ± 0.02, 0.68 ± 0.03, and 0.66 ± 0.03, respectively) were significantly different (p < 0.001) from the corresponding ones for monocular blindness (0.62 ± 0.02, 0.83 ± 0.02, and 0.82 ± 0.02, respectively) and binocular blindness (0.33 ± 0.02, 0.62 ± 0.03, and 0.61 ± 0.03, respectively). Age was inversely proportional to the utility scores in all groups (p < 0.01), decreasing a utility score of 0.006 for every increase in year of age. Conclusion: A sample of the general population and medical students, if faced with facial disfigurement, would undergo a face transplant procedure with a 34 percent chance of death and be willing to trade 12 years of their life to attain perfect health.

Preoperative diplopia: the most important prognostic factor for diplopia after surgical repair of pure orbital blowout fracture.

Background: No consensus exists in the literature regarding the risk factors associated with new or residual diplopia after pure orbital blowout fracture (BOF) repair. Objective: To assess and evaluate the risk factors associated with diplopia after surgical repair of pure BOF. Methods: Patients with pure BOF who were managed surgically were identified in an 11-year period at the McGill University Health Center. The association between new or residual diplopia postsurgical repair and various risk factors was assessed using &khgr;2 and Fisher exact tests, and multivariate analysis was conducted using logistic regression. Results: A total of 61 patient charts were reviewed. Results demonstrated the presence of preoperative diplopia and radiologic evidence of extraocular muscle (EOM) swelling to be strongly associated with diplopia at 6 months after repair (P < 0.05). Patients who presented preoperatively with diplopia had a 9.91 times greater probability of developing diplopia postoperatively (P = 0.035; 95% confidence interval, 1.17-83.80). Conclusions: Preoperative diplopia is the best predictor of the presence of postoperative diplopia after BOF repair. Initial injury to the EOM leading to EOM swelling and preoperative diplopia seems to be the origin of diplopia after surgical repair of pure BOF.

Spatial and temporal localization of WNT signaling proteins in a mouse model of distraction osteogenesis.

While the surgical procedure of distraction osteogenesis (DO) is very successful in the treatment of orthopedic conditions, its major limitation of slow bone formation in the distracted gap has prompted numerous attempts to understand and accelerate this slow bone formation. Interestingly, WNT/FZD signaling has been identified as a critical pathway in mediating bone formation and regeneration but has not yet been studied in the context of DO. The objective of this study was to determine the spatial and temporal localization of endogenous WNT signaling proteins at various times of bone formation in a wild-type mouse model of DO. In this study, the DO protocol performed on mice consisted of three phases: latency (5 days), distraction (12 days), and consolidation (34 days). Our immunohistochemical findings of distracted bone specimens show an increased expression of WNT ligands (WNT4 and WNT10A), receptors (FZD1 and 2, LRP5 and 6), β-catenin, and pathway antagonizers (DKK1; CTBP1 and 2; sFRP1, 2, and 4) during the distraction phase, which were then down-regulated during consolidation. This is the first published report to show an activation of the WNT pathway in DO and could help identify WNT as a potential therapeutic target in accelerating bone regeneration during DO.

Brief Report: CD109 Overexpression Ameliorates Skin Fibrosis in a Mouse Model of Bleomycin-Induced Scleroderma

OBJECTIVE Transforming growth factor β (TGFβ) is a profibrotic cytokine, and its aberrant function is implicated in several types of fibrotic pathologies including scleroderma (systemic sclerosis [SSc]). Multiple lines of evidence show that increased TGFβ signaling contributes to progressive fibrosis in SSc by promoting fibroblast activation, excessive extracellular matrix (ECM) deposition, and dermal thickening. We have previously identified CD109 as a TGFβ coreceptor and have shown that it antagonizes TGFβ signaling and TGFβ-induced ECM expression in vitro in human keratinocytes and fibroblasts. The aim of the present study was to examine the ability of CD109 to prevent skin fibrosis in a mouse model of bleomycin-induced SSc. METHODS Transgenic mice overexpressing CD109 in the epidermis and their wild-type (WT) littermates were injected with bleomycin in phosphate buffered saline (PBS) or with PBS alone every other day for 21 days or 28 days. Dermal thickness and collagen deposition were determined histologically using Massons trichrome and picrosirius red staining. In addition, collagen and fibronectin content was analyzed using Western blotting, and activation of TGFβ signaling was examined by determining phospho-Smad2 and phospho-Smad3 levels using Western blotting and immunohistochemistry. RESULTS Transgenic mice overexpressing CD109 in the epidermis showed resistance to bleomycin-induced skin fibrosis, as evidenced by a significant decrease in dermal thickness, collagen crosslinking, collagen and fibronectin content, and phospho-Smad2/3 levels, as compared to their WT littermates. CONCLUSION Our findings suggest that CD109 inhibits TGFβ signaling and fibrotic responses in experimental murine scleroderma. They also suggest that CD109 regulates dermal-epidermal interactions to decrease extracellular matrix synthesis in the dermis. Thus, CD109 is a potential molecular target for therapeutic intervention in scleroderma.

CD109, a novel TGF-β antagonist, decreases fibrotic responses in a hypoxic wound model

Excessive extracellular matrix deposition that occurs in many fibrotic skin disorders such as hypertrophic scarring and scleroderma is often associated with hypoxia. CD109 is a novel TGF‐β co‐receptor and TGF‐β antagonist shown to inhibit TGF‐β‐induced extracellular matrix protein production in vitro. We examined whether CD109 is able to regulate extracellular matrix deposition under low oxygen tension in vivo using transgenic mice overexpressing CD109 in the epidermis. By creating dorsal bipedicle skin flaps with centrally located excisional wounds in these mice and their wild‐type littermates, we generated a novel murine hypoxic wound model. Mice were sacrificed on 7 or 14 days post‐wounding, and tissues were harvested for histological and biochemical analysis. Hypoxic wounds in both transgenic and wild‐type mice showed increased levels of HIF‐1α and delayed wound closure, validating this model in mice. Hypoxic wounds in CD109 transgenic mice demonstrated decreased collagen type 1 and fibronectin expression, and reduced dermal thickness on day 7 post‐wounding as compared to those in wild‐type mice and to non‐hypoxic control wounds. These results suggest that CD109 decreases extracellular matrix production and fibrotic responses during hypoxic wound healing. Manipulating CD109 levels may have potential therapeutic value for the treatment of fibrotic skin disorders associated with poor oxygen delivery.

Transverse Cervical Artery: Consistent Anatomical Landmarks and Clinical Experience with Its Use as a Recipient Artery in Complex Head and Neck Reconstruction

Background: Many head and neck reconstructions occur in patients with extensive history of surgery or radiation treatment. This leads to complicated free flap reconstructions, especially in choosing recipient vessels in a “frozen neck.” The transverse cervical artery is an optimal second-line recipient artery in head and neck reconstruction. Methods: Seventy-two neck sides in 36 cadavers were dissected, looking for the transverse cervical artery and transverse cervical vein. Anatomical location of these vessels, their diameter, and length were documented. A retrospective analysis on 19 patients who had head and neck reconstruction using the transverse cervical artery as a recipient artery was undertaken as well with regard to outcome of procedures, reason for surgery, previous operations, and use of vein grafts during surgery. Results: The transverse cervical artery was present in 72 of 72 of cadaveric specimens, and was infraclavicular in two of 72 specimens. Transverse cervical artery length ranged from 4.0 to 7.0 cm, and the mean diameter was 2.65 mm. The transverse cervical vein was present in 61 of 72 cadaveric specimens, the length ranged from 4.0 to 7.0 cm, and the mean diameter was 2.90 mm. The transverse cervical artery averaged 33 mm from midline, and branched off the thyrocervical trunk at an average 17 mm superior to the clavicle. Transverse cervical artery stenosis was markedly less in comparison with external carotid artery stenosis. In a 20-year clinical follow-up study, the transverse cervical artery was the recipient artery in 19 patients. A vein graft was used in one patient, and no flap loss occurred in any of the 19 patients. Conclusion: The transverse cervical artery is a reliable and robust option as a recipient artery in free flap head and neck reconstruction.

Complex scalp, skull, and dural defect reconstruction using a turnover "tournedos" myocutaneous free flap.

Background The latissimus dorsi flap is one of the most commonly used flaps for calvarial defect reconstruction. In the setting of radiation and/or chronic infection and when skeletal reconstruction of the cranium is not recommended, standard calvarial reconstruction needs to be refined. The standard use of the latissimus dorsi only was associated with potential dead space over the dura, limited skin paddle size, and potential external contour irregularities. Methods In this study, we present our approach to complex calvarial reconstruction with free tissue transfer without bone grafting while avoiding contour deformities in 1 efficient surgical procedure. We propose the “tournedos” turnover de-epithelialized latissimus dorsi flap, which provides stable dermal and subdermal tissue that will not undergo atrophy over time over the dura. To reach an adequate aesthetic result, we used a uniform, unmeshed, thick split-thickness skin graft over the muscular portion of the tournedos flap. Patients who underwent this procedure, from March 1992 to March 2012, at McGill University Health Center and the Montreal Neurological Institute were included. Results Thirty-three complex microsurgical procedures for oncologic calvarial defect reconstructions were performed from March 1992 to March 2012. Among them, 6 patients benefited from the tournedos procedure. The average age was 74 years. Scalp defects sizes ranged from 4 × 10 to 16 × 18 cm (40–288 cm2). All latissimus dorsi flap donor sites were closed primarily. Patients kept their donor-site drains for approximately 18 days (±5 days). One patient developed a seroma at the donor site after drain removal that was treated conservatively. All patients were satisfied with their reconstructions, and no secondary procedures were necessary. We present our most recent case with good photographic documentation. Conclusions Our approach using the tournedos turnover de-epithelialized free flap provides durable and stable coverage for irradiated and/or previously infected calvarial defects. It is a safe procedure in those challenging complex cases and offers many advantages.

Delayed repair of lateral orbital wall and orbital floor fracture.

Abstract Timing of surgical management of facial fractures may differ from the current standard when an associated severe ophthalmologic injury exists; this may necessitate a delay in repair to protect the patient’s vision. We set out to demonstrate that good functional and aesthetic outcomes can be achieved in cases where zygoma bone fracture repair had to be delayed for more than 21 days after injury with a specific surgical plan. Using the electronic database from Montreal General Hospital, a level I trauma center, a retrospective review of all facial fractures occurring from 1994 to 2009 was performed. Our review returned a total of 22,727 trauma patients admitted to Montreal General Hospital. Of these, 2672 sustained 1 or more facial fractures. Among the facial trauma patients, 945 patients’ injuries included a zygoma fracture, 324 (35.3%) of which were managed operatively. Seven cases had their surgery delayed for more than 21 days after injury, 2 of which were managed using simple osteotomies and plate fixations, without the need for bone grafts. Both patients demonstrated a satisfactory outcome with improvement relative to their preoperative status. We provide a detailed description of our most recent case of a 73-year-old woman in whom the surgical repair of the lateral orbital rim and orbital floor was delayed for 10 weeks to allow healing of her associated traumatic retinal detachment. For patients with associated ocular injuries who cannot undergo orbital fracture repair within 21 days of the trauma, delayed surgery may still result in an acceptable aesthetic result.

The Effect of Exogenous Administration of rhBMP-7 In Distraction Osteogenesis: A Dose-Response Curve and an Alternative Pathway for Bone Formation

IntroductIon: Distraction osteogenesis (DO), a widely used technique for bone and soft tissue formation in numerous craniofacial and limb defects such as traumatic bone loss, congenital anomalies, infection, and malignancies, is not short of limitations. Long consolidation required with multiple associated morbidities is the main limitation related to DO. Thus, we sought to determine the effect of exogenous administration of rhBMP-7 (OP-1) at multiple doses during wild type mice’s tibial DO to ascertain an optimal dose if existing.