Douglas M. Sidle

Controlled reperfusion prevents pulmonary injury after 24 hours of lung preservation

BACKGROUND Posttransplantation lung reperfusion injury continues to be a major problem. We have shown that controlling the initial period of reperfusion limits this injury after 2 hours of warm lung ischemia. The effectiveness of this modality, however, is unknown after longer periods of cold ischemia, which more closely mimics the clinical situation. METHODS After baseline measurements, 10 pigs had the left lung flushed with a modified Euro-Collins solution, explanted, stored at 4 degrees C for 24 hours, and transplanted into 10 other pigs. Five (group 1) underwent uncontrolled reperfusion created by removal of the vascular clamps after implantation of the new left lung, mimicking the clinical situation. The other five (group 2) underwent controlled reperfusion, which we performed by taking blood from the femoral artery, mixing it with a crystalloid solution (using a mixer heater) to make the blood hyperosmolar, alkalotic, and substrate-enriched, and pumping it through a leukocyte-depleting filter into the transplanted lung for 10 minutes at a pressure of 20 to 30 mm Hg before removing the pulmonary artery clamp. The right pulmonary artery and bronchus were then ligated, and left lung function was assessed each hour for 4 hours and compared with baseline. RESULTS Controlled reperfusion (group 2) minimized the reperfusion injury, preserving posttransplant pulmonary compliance (92% +/- 1% versus 68% +/- 1%; p < 0.001), reducing the rise in pulmonary vascular resistance (27% +/- 2% versus 166% +/- 3%; p < 0.001), improving oxygenation (PO2, 425 +/- 14 versus 82 +/- 11 mm Hg; p < 0.001), and lowering myeloperoxidase activity (0.22 +/- 0.02 versus 0.45 +/- 0.02 deltaOD/mg protein per minute; p < 0.001) and tissue edema (83.0% +/- 0.3% versus 84.9% +/- 0.3%; p < 0.001) compared with uncontrolled reperfusion, which resulted in an injury so severe that 3 of 5 pigs died before the 4-hour measurements. CONCLUSIONS After 24 hours of cold ischemia uncontrolled reperfusion results in a severe pulmonary reperfusion injury. This injury is almost completely avoided by controlling the composition (modified solution and white blood cell filter) and conditions (pressure) of the reperfusion. Because this experiment mimics the clinical situation, it suggests surgeons should begin to use this modality to limit reperfusion injury after lung transplantation.

Keloids: Prevention and Management

Keloids result from an abnormal wound-healing process in which the normal regulatory pathways during tissue regeneration and scar remodeling are disrupted. While the pathogenesis of keloids continues to be investigated, numerous treatment options exist. Although prevention of keloid formation is the best management, early recognition of keloid formation is integral in treatment and prevention of recurrence. Surgical resection with adjuvant silicone gel sheeting or triamcinolone injection is common, but can still result in recurrence. New treatments include chemotherapeutics such as 5-fluorouracil, bleomycin, and mitomycin C. Although further clinical investigation is required for newer treatments, initial results are promising.

Augmenting the nasal airway: Beyond septoplasty

Background Nasal airway obstruction is a common complaint of patients presenting to otolaryngology clinics and can be caused by a variety of anatomic factors. A number of advances in the surgical management of nasal airway obstruction have been made over the last century. The objective of this article is to provide descriptions of the surgical procedures used to augment specific anatomic deviations that lead to obstruction of the nasal airway. Methods The descriptions of surgical procedures were derived from a literature review as well as the empiric knowledge of the senior author. Preoperative considerations of nasal anatomy, the nasal airway, and the L-strut are detailed. Results Functional rhinoplasty techniques are reviewed including septoplasty, extracorporeal septoplasty, spreader grafts, batten grafts, alar rim grafts, and correction of caudal septal deviation. Conclusion The symptom, nasal obstruction, may arise from a number of different anatomic and physiological elements. The rhinoplasty surgeon must consider these contributing elements and manage accordingly, to achieve optimal results.

Modification of the orthodromic temporalis tendon transfer technique for reanimation of the paralyzed face.

Objective. To report a modification of the temporalis tendon transfer technique used in facial paralysis where dynamic adjacent muscle transfer is determined to be the best treatment option. Study design. Case series with chart review. Setting. Tertiary care teaching hospital. Subjects and Methods. Review of 10 consecutive patients who underwent orthodromic transfer of the temporalis tendon and the attached coronoid process for the treatment of long-standing facial paralysis. Outcomes measured included patient satisfaction, measurements of oral commissure elevation with smiling, and grading of preoperative and postoperative patient photographs by objective physician observers. Reporting of complications. Results. Patient satisfaction was high, with a mean score of 7.0 (possible score of 10). Four patients were graded by the observer as excellent to superb. The other 6 patients were rated as having fair to good postoperative results. Movement was identified in every patient and ranged from 2.1 to 9.3 mm, with mean movement of the oral commissure of 5.12 mm. One patient developed a seroma at the site of harvest of the fascia that was drained without further complication. Conclusions. This facial reanimation procedure is a novel modification of the temporalis tendon transfer technique in which the coronoid process is transferred in conjunction with the tendon. This technique is minimally invasive and may result in less variability of the postoperative aesthetic result. The procedure allows orthodromic action of the temporalis muscle, is relatively easy to perform, and eliminates the facial asymmetry typically produced by transfer of the origin of the temporalis muscle.

Comparison of intraoperative portable CT scanners in skull base and endoscopic sinus surgery: Single center case series

Precise and safe management of complex skull base lesions can be enhanced by intraoperative computed tomography (CT) scanning. Surgery in these areas requires real-time feedback of anatomic landmarks. Several portable CT scanners are currently available. We present a comparison of our clinical experience with three portable scanners in skull base and craniofacial surgery. We present clinical case series and the participants were from the Northwestern Memorial Hospital. Three scanners are studied: one conventional multidetector CT (MDCT), two digital flat panel cone-beam CT (CBCT) devices. Technical considerations, ease of use, image characteristics, and integration with image guidance are presented for each device. All three scanners provide good quality images. Intraoperative scanning can be used to update the image guidance system in real time. The conventional MDCT is unique in its ability to resolve soft tissue. The flat panel CBCT scanners generally emit lower levels of radiation and have less metal artifact effect. In this series, intraoperative CT scanning was technically feasible and deemed useful in surgical decision-making in 75% of patients. Intraoperative portable CT scanning has significant utility in complex skull base surgery. This technology informs the surgeon of the precise extent of dissection and updates intraoperative stereotactic navigation.

Use of Makeup, Hairstyles, Glasses, and Prosthetics as Adjuncts to Scar Camouflage

Scars after facial trauma or surgery can be a source of distress for patients, and facial plastic surgeons are frequently called upon to help manage them. Although no technique can remove a scar, numerous treatment modalities have been developed to improve facial scar appearance with varying levels of invasiveness. This article reviews techniques that camouflage scars without surgical intervention. Topical scar treatments, camouflage cosmetics, use of hairstyling and glasses, and facial prosthetics are discussed. In addition, professional counseling is provided on selection and application of topical cosmetics for use as part of an office practice.

The Hyaluronic Acid Fillers: Current Understanding of the Tissue Device Interface

The article is a detailed update regarding cosmetic injectable fillers, specifically focusing on hyaluronic acid fillers. Hyaluronic acid-injectable fillers are used extensively for soft tissue volumizing and contouring. Many different hyaluronic acid-injectable fillers are available on the market and differ in terms of hyaluronic acid concentration, particle size, cross-linking density, requisite needle size, duration, stiffness, hydration, presence of lidocaine, type of cross-linking technology, and cost. Hyaluronic acid is a natural component of many soft tissues, is identical across species minimizing immunogenicity has been linked to wound healing and skin regeneration, and is currently actively being studied for tissue engineering purposes. The biomechanical and biochemical effects of HA on the local microenvironment of the injected site are key to its success as a soft tissue filler. Knowledge of the tissue-device interface will help guide the facial practitioner and lead to optimal outcomes for patients.

Determination of Shear Strength of Periosteum Attached to Bone With BioGlue Surgical Adhesive

OBJECTIVE To determine the shear strength of BioGlue Surgical Adhesive (Cryolife Inc, Kennesaw, Georgia) for use in periosteal fixation in endoscopic browplasty. METHODS In a controlled design, the shear strength of periosteal attachment to native bone and that of dissected periosteum affixed to bone with BioGlue surgical adhesive was physiologically determined. Twenty-one periosteum and bone samples were harvested from 3 human cadavers. These samples were tested for maximum shear strength using an Instron Model 5500 universal materials testing machine. Native samples consisted of periosteum still attached to the bone surface, while BioGlue samples consisted of dissected periosteum reattached to the bone surface using BioGlue surgical adhesive. The maximum shear strength attained for each sample was recorded and used to determine if native samples differed from those using BioGlue surgical adhesive. RESULTS The mean (SD) maximum shear strength values obtained during testing were 57.8 (31.7) kPa and 45.9 (27.4) kPa (589.4 [323.3] gram force [gf]/cm(2) and 468.0 [279.4] gf/cm(2)) for native (n=8) and BioGlue (n=9) samples, respectively. There was no statistical difference between the native and BioGlue samples (P> .05) using analysis of variance. CONCLUSION This study demonstrates that the adhesive properties of BioGlue are similar to the strength of attachment of native periosteum to bone and supports the use of BioGlue as an alternative method of fixation for use in endoscopic brow-lifting.

The contralateral injury in blunt laryngeal trauma.

Objectives To present the unique case of a patient who sustained an ipsilateral and contralateral injury after external laryngeal trauma. The authors also explain the dynamics behind this type of injury.

Proprotein convertases generate a highly functional heterodimeric form of thymic stromal lymphopoietin in humans

Rationale: Thymic stromal lymphopoietin (TSLP) is known to be elevated and truncated in nasal polyps (NPs) of patients with chronic rhinosinusitis and might play a significant role in type 2 inflammation in this disease. However, neither the structure nor the role of the truncated products of TSLP has been studied. Objective: We sought to investigate the mechanisms of truncation of TSLP in NPs and the function of the truncated products. Methods: We incubated recombinant human TSLP with NP extracts, and determined the protein sequence of the truncated forms of TSLP using Edman protein sequencing and matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry. We investigated the functional activity of truncated TSLP using a PBMC‐based bioassay. Results: Edman sequencing and mass spectrometry results indicated that NP extracts generated 2 major truncated products, TSLP (residues 29–124) and TSLP (131–159). Interestingly, these 2 products remained linked with disulfide bonds and presented as a dimerized form, TSLP (29–124 + 131–159). We identified that members of the proprotein convertase were rate‐limiting enzymes in the truncation of TSLP between residues 130 and 131 and generated a heterodimeric unstable metabolite TSLP (29–130 + 131–159). Carboxypeptidase N immediately digested 6 amino acids from the C terminus of the longer subunit of TSLP to generate a stable dimerized form, TSLP (29–124 + 131–159), in NPs. These truncations were homeostatic but primate‐specific events. A metabolite TSLP (29–130 + 131–159) strongly activated myeloid dendritic cells and group 2 innate lymphoid cells compared with mature TSLP. Conclusions: Posttranslational modifications control the functional activity of TSLP in humans and overproduction of TSLP may be a key trigger for the amplification of type 2 inflammation in diseases.