Repair of scalp defects using a tissue expander and Marlex mesh.

A simple technique using Marlex mesh and a tissue expander to cover scalp defects is described and two patients are presented. This technique is suitable for medium-sized defects that cannot be closed primarily. Marlex mesh is sutured to the wound edges in lieu of a temporary skin graft and to prevent enlargement of the defect during tissue expansion. The tissue expander is placed under adjacent normal scalp in a subgaleal pocket developed through the scalp defect. The scalp defect is closed secondarily using the expanded scalp flap. This technique was performed in two patients with satisfactory results. Marlex mesh obviates the need for a temporary skin graft to cover the scalp defect.     

Extensive and complex defects of the scalp, middle third of the face, and palate: the role of microsurgical reconstruction

Twenty-one patients with gigantic defects of the scalp and middle third of the face and palate following excision of neglected or recurrent tumors, burns, and infections have undergone microsurgical reconstruction. Wide resection of the middle third of the face, orbit, and palate requires "complex" three-dimensional volume reconstruction, whereas extensive defects of the scalp and skull (exceeding 80 cm2) require coverage of the larger surface area soft-tissue defect and the exposed brain and dura. The latissimus dorsi free-muscle flap and split-thickness skin graft have become our methods of choice for extensive scalp and skull defects. The latissimus dorsi musculocutaneous free flap is preferable for reconstruction of complex palatal and external skin and orbital defects of the middle third of the face. Microsurgical free-tissue transfer reliably frees the oncologic surgeon from the constraints imposed by conventional reconstructive techniques and may therefore allow improved curative or at least palliative resection of these extensive tumors.     

Geometric considerations in the design of rotation flaps in the scalp and forehead region

The classical transposition and rotation flaps are well known. Cosmetic considerations in the scalp and forehead region limit the use of a flap design that requires a skin graft for a donor defect. On sound geometric principles, the classical flap designs are suitably modified here to have a somewhat equal proportion of transposition and rotation. This "modified rotation flap" design works to a maximum advantage in the inextensible region of the scalp and forehead by providing single-stage primary closure of moderate to large defects. No backcuts are ever necessary with this flap design. Use of this principle to modify the rotation flap design for closure of an extended midline forehead defect following rhinoplasty allows a still wider (up to 6.5 cm) midline forehead flap to be available for rhinoplasty with primary closure of the donor defect.     

Aplasia cutis congenita with skull defect in a monozygotic twin after exposure to methimazole in utero

BACKGROUND: Aplasia cutis congenita (ACC) is a condition in which localized or widespread areas of skin are absent at birth. Defective lesions show complete absence of all layers of skin, occasionally extending to skull or dura. ACC is etiologically heterogeneous; many different etiologies including teratogens have been documented. CASE: We describe the first reported case of a monozygotic twin with ACC after exposure to methimazole in utero. The female patient was born at 36 weeks gestation as the first child of monozygotic twins. The mother received methimazole between the 11th and 17th weeks of pregnancy because of transient hyperthyroidism. The second child did not have ACC. The patient had defects of the scalp, skull, and dura (7 x 5 cm) on the sagittal line of the parieto-occipital region. No other malformations were noted. The scalp defect has been treated daily with sterile physiological saline and petrolatum dressing in addition to intravenous antibiotics. Trafermin, a recombinant human fibroblast growth factor, was sprayed from day 6 to promote epithelialization of the scalp defect. On day 21, she had high fever due to infection of the defect lesion, which was controlled by povidone iodine dressing and intravenous antibiotics. The defect of the scalp was well healed after 6 weeks, but the skull defect remained unclosed. CONCLUSIONS: We describe a rare case of a monozygotic twin with ACC and skull defect after methimazole exposure in utero. The findings of our case suggest that methimazole is a potential teratogen of ACC.     

Defect Engineering in Manganese‐Based Oxides for Aqueous Rechargeable Zinc‐Ion Batteries: A Review

The development of advanced cathode materials for aqueous the zinc ion battery (ZIB) represents a crucial step toward building future large‐scale green energy conversion and storage systems. Recently, significant progress has been achieved in the development of manganese‐based oxides for ZIB via defect engineering, whereby the intrinsic capacity and energy density have been enhanced. In this review, an overview of the recent progress in the defect engineering of manganese‐based oxides for aqueous ZIBs is summarized in the following order: 1) the structures and properties of the commonly used manganese‐based oxides, 2) the classification of the various types of defect engineering commonly reported, 3) the various strategies used to create defects in materials, and 4) the effects of the various types of defect engineering on the electrochemical performance of manganese‐based oxides. Finally, a perspective on the defect engineering of manganese‐based oxides is proposed to further enhance their electrochemical performance as a ZIB cathode.     

Bipedicled fronto-occipital flap for reconstruction of postoncologic defects of the lateral scalp

Presented here are two clinical cases of extensive defects of the scalp secondary to surgical resection of invasive basal cell carcinoma on the parietal region, successfully treated by means of very large, bipedicled fronto-occipital flaps, based anteriorly on the supratrochlear-supraorbital vessels and posteriorly on the occipital and posterior auricular vessels. Considering both the location and the large size of the scalp defects, different surgical techniques are discussed and the potential use of bipedicled scalp flaps is considered, designed either sagittally or coronally as fronto-occipital or temporo-temporal flaps. The bipedicled fronto-occipital scalp flap is believed to represent a simple, secure, and useful reconstructive procedure for cutaneous coverage of extensive defects located on the lateral scalp.     

Improved technique for a one-stage repair of significant defects of the ear

An improved technique for repair of severe acquired partial defects of the auricle in one stage is described. The common postauricular flap with its base on the margin of the auricular defect is usually unable to repair a severe partial auricular defect in one stage because of the limited length of the flap. The authors developed this technique by means of lengthening the flap with a piece of subcutaneous tissue of the scalp, so that the ear framework can be covered completely in one stage. All flaps in this group survived totally. Seven patients with severe acquired partial defects of the auricle underwent this procedure, and good results were obtained.     

Prefabricated galeal flap based on superficial temporal and posterior auricular vessels

Scalp layers are widely used in reconstructive procedures. The authors used prefabricated galeal flaps based on the superficial temporal or postauricular vessels for ear, cheek, mandible, and cranium reconstructions in three cases. In case 1, synchronous beard and ear reconstructions were accomplished by using the temporoparietal and retroauricular flaps. In case 2, a buccomandibular defect was reconstructed by transposing the supra-auricular and retroauricular galea with prefabricated bone and skin. In case 3, an epidural hematoma in the left frontoparietal area was evacuated after a circular craniectomy. The harvested bone was not put back on the defect area but buried between the periosteal and galeal layers because of brain edema. These layers were raised as an osteogaleoperiosteal flap and transposed onto the defect area after 7 weeks. When used with a prefabrication method, scalp layers offer versatile options for repairing composite defects of the head region. A galeal flap based on the posterior auricular vessels is practical and reliable in reconstructive procedures. The authors suggest that this flap is an option in cases in which the temporoparietal fascia artery or the superficial temporal artery is not available. Prefabrication of the harvested cranial bone inside the adjacent tissues offers several advantages in that a viable bone is provided at the end of the procedure, intervention at a distant area is avoided, the graft is placed on osteogenic tissue (periosteum) that is also transposed onto the defect, and sophisticated procedures such as microsurgical techniques are not needed.     

Factors Affecting the Ability of the Spectral Domain Optical Coherence Tomograph to Detect Photographic Retinal Nerve Fiber Layer Defects

Purpose

To evaluate the ability of normative database classification (color-coded maps) of spectral domain optical coherence tomograph (SDOCT) in detecting wedge shaped retinal nerve fiber layer (RNFL) defects identified on photographs and the factors affecting the ability of SDOCT in detecting these RNFL defects.

Methods

In a cross-sectional study, 238 eyes (476 RNFL quadrants) of 172 normal subjects and 85 eyes (103 RNFL quadrants with wedge shaped RNFL defects) of 66 glaucoma patients underwent RNFL imaging with SDOCT. Logistic regression models were used to evaluate the factors associated with false positive and false negative RNFL classifications of the color-coded maps of SDOCT.

Results

False positive classification at a p value of <5% was seen in 108 of 476 quadrants (22.8%). False negative classification at a p value of <5% was seen in 16 of 103 quadrants (15.5%). Of the 103 quadrants with RNFL defects, 64 showed a corresponding VF defect in the opposite hemisphere and 39 were preperimetric. Higher signal strength index (SSI) of the scan was less likely to have a false positive classification (odds ratio: 0.97, p = 0.01). Presence of an associated visual field defect (odds ratio: 0.17, p = 0.01) and inferior quadrant RNFL defects as compared to superior (odds ratio: 0.24, p = 0.04) were less likely to show false negative classifications.

Conclusions

Scans with lower signal strengths were more likely to show false positive RNFL classifications, and preperimetric and superior quadrant RNFL defects were more likely to show false negative classifications on color-coded maps of SDOCT.     

Reconstruction of large cranial defects in the presence of heavy radiation damage and infection utilizing tissue transferred by microvascular anastomoses

Six cases of large defects of the scalp, skull, and dura following tumor ablation and radiation are presented. Each was accompanied by chronic infection in the irradiated defect. Efforts to reconstruct the resulting defects with local flaps were not successful. One-stage reconstruction was then accomplished in each case utilizing a latissimus dorsi musculocutaneous or myo-osteocutaneous free flap transferred by microvascular anastomoses. The versatility of the latissimus dorsi musculocutaneous and/or osseous flap allows single-stage reconstruction of these complex defects.     

Microvascular reconstruction of the hypopharynx: defect classification,treatment algorithm,and functional outcome based on 165 consecutive cases

The objectives of this study were three-fold: to develop a scheme for classification of hypopharyngeal defects, to establish a reconstructive algorithm based on this system, and to assess the functional outcome of such reconstruction. This study is a retrospective review of a 14-year experience with 165 consecutive microvascular reconstructions of the hypopharynx in 160 patients. The average patient age was 59 years (95 percent CI, 37 to 81). Thirty-four patients were operated on for recurrent disease; 71 had preoperative radiotherapy. Partial defects were reconstructed with radial forearm flaps (n = 52); circumferential defects were reconstructed with jejunum (n = 90); and extensive, noncircumferential longitudinal defects were reconstructed with rectus abdominis flaps (n = 23). The overall free flap success rate was 98 percent. Six flaps required reexploration, two of which were salvaged. The incidence of fistula was 7 percent and stricture, 4 percent. Preoperative radiotherapy was significantly associated with risk of recipient site complications (OR, 2.3; 95 percent CI, 1.0 to 5.0). Follow-up data were available on 95 percent of patients: 53 percent were able to tolerate an unrestricted diet, 23 percent a soft diet, 12 percent liquids only, and 12 percent were limited to tube feedings. The treatment algorithm for microvascular hypopharyngeal reconstruction is based on the type of defect with partial defects with radial forearm flaps, circumferential defects reconstructed with free jejunal flaps, and extensive, multilevel defects reconstructed with rectus abdominis myocutaneous flaps. Microvascular reconstruction of pharyngeal defects is highly successful with few postoperative complications. With appropriate flap selection, functional outcome can be optimized.     

Prenatal care demand and its effects on birth outcomes by birth defect status in Argentina

Our objective was to identify determinants of prenatal care demand and evaluate the effects of this demand on low birth weight and preterm birth. Delay in initiating prenatal care was modeled as a function of pregnancy risk indicators, enabling factors, and regional characteristics. Conditional maximum likelihood (CML) estimation was used to model self-selection into prenatal care use when estimating its effectiveness. Birth registry data was collected post delivery on infants with and without common birth defects born in 1995-2002 in Argentina using a standard procedure. Several maternal health and fertility indicators had significant effects on prenatal care use. In the group without birth defects, prenatal care delay increased significantly LBW and preterm birth when accounting for self-selection using the CML model but not in the standard probit model. Prenatal care was found to be ineffective on average in the birth defect group. The self-selection of higher risk women into earlier initiation of prenatal care resulted in underestimation of prenatal care effectiveness when using a standard probit model with several covariates. Large improvements in birth outcomes are suggested with earlier initiation of prenatal care for pregnancies uncomplicated with birth defects in Argentina, implying large opportunity costs from the long waiting time observed in this sample (about 17 weeks on average). The suggested ineffectiveness for pregnancies complicated with common birth defects deserves further research.     

Scalp expansion in the treatment of male pattern baldness

Tissue expansion has been extremely valuable in the treatment of traumatic scalp defects. We have recently used expansion techniques in the treatment of male pattern baldness. Expansion has been used in conjunction with scalp-reduction procedures and pedicled hair-bearing flaps. Flaps have been designed as Juri flaps, and in one patient, a new posteriorly based flap was used. This design gives the advantage of a more natural-appearing hairline and forward-growing hair. The major advantage of tissue expansion in the treatment of male pattern baldness is that it generates new hair-bearing scalp. The increase in vascularity which occurs during expansion allows for large, safe, and predictable flaps. Donor sites are also relatively easily closed. The disadvantages of expansion include the need for two or more surgical procedures and multiple office visits. There is also some discomfort following expansion and a cosmetic defect as the expanders become larger. Complications include infection, exposure or extrusion, deflation, and hair loss. Tissue expansion combined with scalp reduction and pedicled hair-bearing flaps have proved to be a valuable technique in the treatment of male pattern baldness with a high degree of patient satisfaction.     

An algorithm for abdominal wall reconstruction

Acquired abdominal wall defects result from trauma, previous surgery, infection, and tumor resection. The correction of complex defects is a challenge to both plastic and reconstructive and general surgeons. The anatomy of the abdominal wall, as well as considerations in patient assessment and surgical planning, are discussed. A simple classification of abdominal wall defects based on size, depth, and location is provided. Publications regarding the various abdominal reconstruction techniques are reviewed and summarized to familiarize the reader with the treatment options for each particular defect. Finally, an algorithm is presented to guide the surgeon in selecting the optimal reconstructive technique.     

Treating Cutis Verticis Gyrata Using Skin Expansion Method

The objective of this study was to evaluate the feasibility and clinical effect of repairing scalp defect after the excision of cutis verticis gyrata using expanded scalp skin flaps. For this purpose, 8 patients with cutis verticis gyrata were subjected to scalp skin expander implantation under the skin. After saline injection and scalp expansion for 2–3 months, the cutis verticis gyrata was excised and the expanded scalp flaps were applied to recover the skin defect. As a result, the flaps and hair grew well without contractures and significant scarring, suggesting that this method is useful for surgical correction of cutis verticis gyrata.     

耳后头皮推进瓣急诊即刻修复创伤性耳郭部分缺损的临床效果观察

目的:探讨耳后头皮瓣急诊即刻修复耳郭部分缺损的可行性与临床效果。方法:对2013年1-12月来我院急诊的7例外伤后耳郭部分缺损的患者(均为男性,年龄22-50岁;其中右耳4例,左耳3例)采用耳后头皮推进瓣即刻修复,以耳郭缺损耳后皮肤及头皮皮肤做推进瓣,将断离的耳郭去皮保留软骨与耳郭断端软骨缝合形成软骨支架,推进皮瓣部分卷曲缝合形成耳轮结构修复耳郭缺损。结果:7例耳郭部分缺损均在急诊环境下即刻修复,耳郭大小和形态满意,颅耳角略变小,随访3~6月耳郭形态稳定。结论:耳后头皮推进瓣卷曲缝合可在急诊条件下即刻修复耳郭部分缺损,具有治疗周期短,一次达到较满意外形的优点,对于无条件行二期手术的患者具有较大意义,其远期效果尚有待进一步随访。     

A morphogenetic classification of craniofacial malformations

A new classification of malformations of the face and cranium is proposed, based on embryologic studies and observations concerning a great number of patients seen by the authors. First of all, one should distinguish between cerebral craniofacial (with brain and/or eyes involved) and craniofacial malformations. Craniofacial malformations may be characterized by dysostosis and by synostosis. Malformations with dysostosis may be produced by transformation as well as differentiation defects. Synostosis is always caused by a differentiation defect. A new nomenclature is introduced.     

Recent Progresses on Defect Passivation toward Efficient Perovskite Solar Cells

The disorderly distribution of defects in the perovskite or at the grain boundaries, surfaces, and interfaces, which seriously affect carrier transport through the formation of nonradiative recombination centers, hinders the further improvement on the power conversion efficiency (PCE) of perovskite solar cells (PSCs). Several defect passivation strategies have been confirmed as an efficient approach for promoting the performance of PSCs. Herein, recent progress in the defect passivation toward efficient perovskite solar cells are summarized, and a classification of common passivation strategies that elaborate the mechanism according to the location of the defects and the type of passivation agent is presented. Finally, this review offers likely prospects for future trends in the development of passivation strategies.     

Some Thoughts on the Etiology of Human Diabetes

A suggested classification of the possible causes of diabetes mellitus is presented, based on the assumption that the disorder is genetically controlled. On the one hand there are factors which produce a failure in the formation, liberation, or action of insulin; on the other hand, there are factors which produce an increased formation, liberation, or action of substances which, in excess, have diabetogenic effects. As well, genetic defects that give rise to diabetes mellitus may involve insulin-dependent reactions or, as a theoretical consideration, be independent of hormonal actions. Final clarification of the physiological mechanisms by which each of the causes produces abnormalities in metabolism offers a challenge for future investigation, as well as elucidation of the primary defect or defects in diabetes mellitus.